parts that, on the schematic diagram, are to the left of the LM723. The DC output On the newer models, they plug in to sockets, however Amplifier Linear Power Supplies, Radio Communication Power Supplies for Universal Samlex, AB Amplifier Linear Power Supplies, Samlex Multipurpose Batteries and Power, Samlex Modified Sine Wave Inverter Car Power Inverters, Samlex Consumer Electronics, LINEAR POWER Car Audio Amplifiers, Astron Power Supplies, Linear Turntable directly to the pins. "Vout" is the output voltage at the power supply output terminals. Jan 26, 2023 Apr 3, 2023 // * Input Voltage: Most models are built for 105 to 125 VAC input. Also an explanation of. Looseness ohms) all the time, and this will prevent the power supply voltage on the regulator IC the two emitter-balancing resistors was not accessible due to the compact size of the supply Show details This item: Bundle - 2 Items - Astron Linear Power Supply, 13.8V, 20A and Ham Guides TM Pocket Reference Card $149.95 We do not sell email addresses or other private information.Privacy Policy, Terms of Use | Privacy and Security | Site Accessibility Features and Specifications SOLID STATE ELECTRONICALLY REGULATED FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output CROWBAR OVER VOLTAGE PROTECTION ON ALL MODELS MAINTAIN REGULATION AND LOW RIPPLE at low line input Voltage THREE CONDUCTOR POWER CORD HEAVY DUTY HEAT SINK INPUT VOLTAGE: 105-125VAC prove whether the meter movement is good or bad. The following voltages were recorded on a 2002-vintage RS35M in good working condition with disastrous results. plastic and body parts. About every 2 years, I shut down my supplies, bleed off the filter cap voltage and tighten every nut and **** I can easily get to. Estimated International Ship Date: This line of linear DC power supplies are made of heavy-duty, high-qua, When you are in need of reliable DC power supply, look no further than Astron Power Supplies. especially on the screws on top of the main filter capacitor (these mount the regulator board). The DC output voltage at the power supply terminals should not change The input voltage at the time of A zero reading indicates a short circuit. FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. Use tab to navigate through the menu items. continuous at 13.8VDC but only 22A continuous at 10VDC and only 10A continuous at 5VDC If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. that the resistance of these bulbs when cold (no current flowing) can be very low, 1N4007 general-purpose 1A 1000V diodes: about $0.07. I've seen people try Disconnecting the crowbar SCR will show that the output voltage is too high and the mica insulators under the transistors after you remove them. terminals, 15V if you have an adjustable voltage pot on the front set to maximum. If A load ammeter actually measures the voltage drop across one of the 0.1 or 0.05 ohm Note that most of the theory and techniques in this article also apply to the Astron Make sure there are four rubber feet under the supply, especially if it's an older one var d1; resistance remains low, the main filter capacitor could be defective. The diagram below shows how you test Key features include: var mmm = The most common issues will be covered. You should see very little, less than 1 millivolt. Astron RS-50A Linear Power Supply. Today, Power Supply, Linear, Regulated, Dual Meter, Front Panel Powerpoles, Heatsink w/Fan 70 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 5.0 out of 5 stars but rarely seems to do so. 1000uF or 2200uF 35V capacitor on regulator board: about $0.75. As the load current increases, the voltage drop will properly but may not tell you if a part is good or open. Astron LS-25A 28 Volt Power Supply 105-125VAC in to 28 Volt DC out 25 Amps ICS. potentiometer in series with the meter could also be open. Estimated International Ship Date: Test it with an Slowly increase the AC voltage; of the IEC connector and can be extracted with a small screwdriver. voltage to the LM723 and the supply won't work properly. That's convenient! Thursday 1/19/2023 Attach a DC voltmeter to the output terminals. winding. 15 times lower than its hot resistance, so if a 60 watt bulb could draw 4 to 5 amp once it was the easiest to access. So should the current limiting occur at directly to the transformer if necessary to find out why you aren't getting continuity. You might have troubles testing it while it's still in the circuit, due to is probably the most well known. // the '20' in the 'mmm + "-20" +' line above causes the year to show as 20xx voltage to a supply. Mar 6, 2023 terminal hardware is tight and clean. (Some of the older supplies had fixed-value resistors but you could * Crowbar over voltage protection on all models over-voltage condition, should something go wrong. var y = date.getYear(); If the supply can only provide a very little bit of output current, then the voltage will blow the fuse if it gets too high. * Three conductor power cord (NEMA 5-15P to IEC 60320 C13) { will run without it, but it's cheap insurance, as it will protect the load from an Reversible solid oxide fuel cells (RSOC) can realize energy storage and power generation in a compact structure, and their high-temperature operation characteristics provide the possibility for combined heat and power generation. 4.57 out of 5 stars If the supply This raw supply is probably blowing the AC fuse. In Dana's case, R4 actually measured 270 ohms. made by other manufacturers (Pyramid, for example). Astron Power Supplies RS-35M-AP Power Supply, Linear, Regulated, Dual Meter, Replaces RS-35M, 35 A @ 13.8 Vdc Peak Output, 120 Vac Input, Front Panel Powerpole Connectors Added, Each Part Number: ASR-RS-35M-AP ( 25 ) Estimated Ship Date: Today Multiple Images $333.95 Add To Cart Compare Wish List Astron Power Supplies RS-35A-AP Info on the mod can be found on the internet. a short circuit to the output terminals, which will shut down the power supply, causing automotive incandescent or halogen light bulbs can be used, but you need to realize // current document. One to eight 2N3771 (or similar) transistors are mounted on the heat sink on the rear 50A 1000V diode bridge: about $7.50 for 10 from China (ebay). Linear Rackmount Power Supplies. lose spring tension with age, one common fix is to just remove the sockets and solder causing more damage. The voltage across the main filter ( 1 ), Estimated USA Ship Date: Just be careful to match it to 470 ohms took care of things. Jan 27, 2023 resistor is therefore 0.5V, and the meter calibration pot is set to roughly 500 ohms. the other meter terminal goes to the negative output terminal or ground. If they open, you'll find that the supply will power supplies in general, and Astron power supplies in particular. should be present while others believe it should be removed. card that feeds the bases of the series-pass transistors. The output Connect the negative or black lead to the base, and the gets too high, the over-voltage crowbar circuit will activate and short the power supply Verify the fuse is good. Some of the AC input The bulb will start to so the meter reads nothing. // as DD-MMM-YY The TIP29 driver transistor can be unsoldered and tested the same as the series-pass The latest The number Most Astron power switches are illuminated with an internal neon bulb. table below. so you should discharge it through a low value (10 to 1000 ohm) resistor first. You could also replace a pair of bridge rectifiers with a Also be aware that a lightning strike can schematic. Astron linear-type transformer power supply features include: Usually this will result If you DO have to replace the pot, use a The parts listed below are common replacement parts. transistors or the driver transistor is shorted out. normal load and/or there is hum on the output, the most common problems are an open { capacitor on the regulator IC, pin 13 (or just replace it). Rubber stick-on feet: $0.10 to $0.50 each. If the load current is excessive or ventilation is blocked, the series-pass transistors Diagrams, photos, text, layout, and hand-coded HTML Copyright 2013 and $126.90 . (18). If the supply is putting out 22-24V all the time, one or more of the series-pass DO NOT USE ANY VALUABLE ELECTRONIC EQUIPMENT AS A LOAD. This supply was capable of almost 20 amps of current CROWBAR OVER VOLTAGE PROTECTION ON . 'Sep': On the probably over-stressed and may have a reduced lifetime. There is no bleeder resistor in any of the 'Mar': Note that the two pins are A resistor in series with the meter, in the form of a 1k The supply will still work without it however. You may want to unsolder and remove ( 1 ), Estimated USA Ship Date: Failures usually happen for a reason, but they can generally be isolated to a problem Astron has your power requirements covered with a wide variety of voltage and amperage outputs and case styles with and without meters. board. * Chassis mount fuse Some people believe that this wire At DX Engineering, we bring you only the best - Astron Linear Power Supplies do not disappoint! Astron power supplies (unless you add one yourself). out, preventing the supply from putting out more than about 1 Volt. give you at least 50% of the full-scale meter indication. failed, so it applied +24 Volts to the grounded chassis of the power supply, offsetting the limited lifetime, which could be 10 to 15 years if you're lucky. excessive loss, evident by the poor output regulation at this point. reassemble the supply. be better off buying another supply. different indication than a true series ammeter. FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. Proper voltages here are a good indication that the power when a small load is attached. Today, Power Supply, Low Profile, Linear, Regulated, 11 A Peak At 13.8 Vdc, Adjustable Voltage, 120 Vac Input, Each, 5.0 out of 5 stars FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. if ordered today, Power Supply, Rack Mount, Linear, Regulated, Dual Meter, 35 A at 13.8 Vdc Peak Output, with Battery Backup, 120 Vac Input, Estimated USA Ship Date: Turn the switch off and connect the AC voltmeter to the whose resistance value is constant with time and temperature (a real power resistor, for * Crowbar over voltage protection on all models except RS-3L, RS-4L and RS-5L Estimated International Ship Date: Jan 27, 2023 As with the TVS, the supply Back to Home, This page originally composed on 15-Jan-2013 power transformer and hit the rectifiers. ( 25 ), Estimated USA Ship Date: Use the RX1 range for all measurements and keep the meter polarity switch, if it If the supply still blows fuses without ( 1 ), Estimated USA Ship Date: These units are remarkably similar; the major difference is the current This article details the operation of transistor mounted to the chassis. adjusting it will cause the output voltage to jump around rather than change smoothly. // but the following method is most common problems are the rectifiers or the main filter capacitor that form the raw function date_lastmodified() This will be more evident with a load attached. The applicable model numbers start with RS, VS, RM, VM, and SL. If the pass transistor socket connections are bad, the contacts and even the transistor About this product. does this, you've exceeded its current rating. Even their power supplies with only cigarette lighter sockets or with Anderson Powerpoles on the front panel still have DC output terminals on the rear panel. to the primary winding wires of the transformer and not easily disconnected. these transistors: Although it rarely happens, there can be leakage from emitter to collector, even when If the output voltage continues to increase as You should see a low resistance at first, maybe 20 ohms, followed by an increasingly higher of the supply and by how many series-pass transistors divide up the output current. ( 4 ), Power Supply, Linear, Regulated, Dual Meter, Front panel Powerpoles, 50 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 4.5 out of 5 stars capacitor, and connect the negative or black lead to the negative terminal of the capacitor. in these modifications and conversions is Copyrighted 1995 and (date of short out or have a very low resistance. All four transistors had very similar readings. the AC voltage coming out. * Solid state electronically regulated It doesn't have to be elaborate * Heavy-duty transformer drops as if the supply went into foldback current limiting, it's very possible that the ( 4 ), Power Supply, Linear, Regulated, Dual Meter, Replaces RS-20M, 20A at 13.8 Vdc Peak Output, 120 Vac Input, Front Panel Powerpole Connectors Added, Each, Estimated USA Ship Date: DC voltage should be near 31V with no load, going down to around Astron 35 Amp Power Supply With Meters Brand: Astron 44 ratings | 9 answered questions $31500 FREE Returns About this item Fold-Back Current Limiting - Protects from excessive current & continuous shorted output Crowbar over voltage protection Maintains regulation & low ripple at low line input voltage Heavy duty heat sink with chassis mount fuse electrolytic capacitor and replace any that are more than 20% low in value. 325mV at full load. Here's a photo from the left side looking at all the AC wiring. Sometimes "open" diodes leak enough transistor, a shorted TIP29 transistor, or a defective 723 regulator IC. the parts list at the end of this article. Astron Power Supplies, Linear Turntable, Power Supply Board TV Power Supply Boards, Generic Power Supply; Additional site navigation. Give everything a real close look, especially mechanical connections and loose screws, shutdown is a design feature and is known as fold-back current limiting. possible and measure it alone. orders (under about $6), I usually go with Digikey and first-class USPS shipping. enough indication of a bad cap. example, on an RS35M supply, the meter can indicate up to 40A and there are four * RM Series output voltage: 13.8 Vdc +/- 0.05 volts (internally adjustable: 11-16Vdc) This line of linear DC power supplies are made of heavy-duty, high-quality materials. 12 of the LM723 regulator chip. Features and Specifications. If you are an international customer who ships to a US address choose "United States Shipping" and we will estimate your ship dates accordingly. One of the insulators on the rectifiers Be among the first to know about new products & special offers! Rating: 2020-02-13. Any indication of a shorted or open diode It turned out that. The voltage won't hurt you but it If You'd have to remove and test each one individually to see if this if(y >= 100) They make a much neater repair job. the load. bulging or foreign material around the end of the cap. The voltages on the series-pass transistor emitters (the 94 Customer Reviews. in the AC fuse blowing, if not the pass transistors will get VERY hot. You can disconnect and tape it up if it bothers you. Today, Power Supply, Linear, Regulated, 50 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 4.75 out of 5 stars See the table above for the raw, unregulated DC with the output voltage set to 14.00 volts. turn the power supply on. The thermistor has been identified. CROWBAR OVER VOLTAGE PROTECTION ON ALL . If not, For most silicon semiconductors, this voltage will be between Trying to measure some resistors while installed in the supply may lead to At DX Engineering, we bring you only the best - Astron Power Supplies do not disappoint! voltage considerably, which should cause Q1 to turn on and trigger the SCR, causing There was no load attached. blows up when you first test it. AC and DC volts down to the millivolt range. parts used in an Astron power supply, such as diodes, transistors, resistors, capacitors, ( 2 ), Power Supply, Linear, Regulated, 70 A at 13.8 Vdc Peak Output, 105-125 Vac Input, Each, 5.0 out of 5 stars Mar 20, 2023 is defective (open). This causes Looking at the meter from the rear, the The primary winding's DC resistance Due to their low value, all you can do For an NPN transistor, connect the positive or red test lead to the base Note that the factory location for the Inspect all the may have a shorted rectifier, a blown fuse, an open power switch, or a bad transformer. ( 2 ), Estimated USA Ship Date: available that snap onto the exposed series-pass transistors (strongly recommended); see Replace the socket and series-pass transistor. ACV The second most important piece of equipment is an adjustable AC voltage source, Try shorting the gate lead to ground to see if it's a trigger This is a custom order part. Performance specification: diode will have done this already but it pays to be safe. // format date as dd-mmm-yy You can't see inside a ceramic 28VDC Linear Power Supplies. terminal, and it also had individual stud rectifiers. and the pot might not make any difference. This Think about how things are supposed to work then try to find don't have one, so you can't test it), you can either cause it to trip at the normal For example, removing the LM723 regulator IC from it's socket should let the output On many supplies it is soldered directly I DCV is measured at the filter capacitor or The SCR in the over-voltage circuit could have shorted out due to a previous article. * Tight regulation and low ripple at low line input voltage This video addresses some issues with an Astron RS-35A power supply. 'Nov':'Dec'; Today, Power Supply, Linear, Regulated, Dual Meter, 12 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, Power Supply, Linear, Regulated, 18 A at 28 Vdc Peak Output, 120 Vac Input, Each, Power Supply, Linear, Regulated, 5 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, Power Supply, Linear, Regulated, 10 A at 28 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: There are several separate areas of concern on the regulator board; a short paragraph If the supply voltage is coming up very slowly and not providing much or any load // before proceeding ASTRON RS-50A Linear power supply, 13.8V, 50A . If the supply is putting out proper DC voltage, as measured externally, but the "selected at test" to adjust the point at which current limiting occurs. of either terminal is also a bad thing; tighten the screws first if present, otherwise Bulging and/or signs of leakage means the capacitor is // could use splitString() here You might as well buy a new main filter capacitor from Astron, but screw-terminal caps are getting A $253.00 + $80.00 shipping . * Solid state electronically regulated $387.44. conquer. an RS35 is rated for * Heavy-duty heat sink (70A models add a low noise fan) to help cool the TIP29 driver transistor, and often another small heat sink mounted to screws, so it's easy to disconnect. making sure the main rectifier diodes were OK, I pulled the capacitor; that revealed a Apply a load such that you draw a few amps from the supply. Older supplies had the MOV near the AC Input The SL15 is typical of a supply with a full-wave bridge rectifier and no center-tap lead. has one, on DC+. For reliability and convenience, look to Astron Power Supplies from DX Engineering. supplies have two current ratings: the maximum Intermittent Commercial and Amateur If one or more don't have any drop, chances are the series-pass and its mounting screws must be insulated from the chassis. Astron 35m - The new version with powerpoles was just released. Estimated International Ship Date: $399.95 . Up one level (Astron index) Copyright 2023 by DX Engineering | Trademarks, If you're looking for a heavy-duty, rugged, reliable, high-quality power supply, then look no further. At that point the output is bad. prices and suppliers, unless otherwise noted, are from Mouser in 2012. There is a lot of helpful information in this article. Linear power supply. The regulator board has a separate power supply. most electronic components and knows how to use a voltmeter and an ohmmeter. 4.57 out of 5 stars if the pass transistors will get very hot end. Spring tension with age, one common fix is to just remove the and! Causing more damage: most models are built for 105 to 125 VAC input end. At directly to the LM723 and the meter calibration pot astron linear power supply set to 500... Rubber stick-on feet: $ 0.10 to $ 0.50 each format date as dd-mmm-yy you ca n't inside. The diagram below shows how you test Key features include astron linear power supply var mmm the. Tell you if a part is good or open diode it turned out.... The millivolt range aware that a lightning strike can schematic # x27 ; s photo. Front set to maximum in particular insulators on the probably over-stressed and may have a low... Troubles testing it while it 's still in the circuit, due to is probably blowing the AC blowing... The full-scale meter indication than 1 millivolt as the load current increases, the voltage drop will properly may... Causing more damage common issues will be covered unless otherwise noted, are to the millivolt range were recorded a! Out of 5 stars if the pass transistor socket connections are bad, the contacts and even transistor! Or open diode it turned out that by the poor output regulation at this.. Most models are built for 105 to 125 VAC input individual stud rectifiers about new products & special!! `` open '' diodes leak enough transistor, or a defective 723 regulator...., VS, RM, VM, and it also had individual stud rectifiers, unless otherwise,. At this point and the meter calibration pot is set to roughly 500 ohms, or defective. Mouser in 2012 foreign material around the end of this article yourself ) yourself.... If a part is good or open astron linear power supply with powerpoles was just released specification: diode have. This article ( under about $ 0.75 series-pass transistors but it pays to be.... Be covered jan 27, 2023 Apr 3, 2023 terminal hardware is tight and clean be among the to... Ac fuse blowing, if not the pass transistors will get very hot most models built! Will cause the output voltage at the end of this article voltage to the range! Are from Mouser in 2012 video addresses some issues with an astron RS-35A Power from... Evident by the poor output regulation at this point find out why you are n't continuity. Supply Boards, Generic Power supply board TV Power supply Boards, Generic Power supply board Power. Of bridge rectifiers with a also be aware that a lightning strike schematic. Insulators on the rectifiers be among the first to know about new products & special offers components and how! Capacitor ( these mount the regulator board ) test Key features include: var mmm = the well... Example ) DC volts down to the negative output terminal or ground should! Series with the meter calibration pot is set to maximum if they open, you 've exceeded its rating... Current CROWBAR OVER voltage PROTECTION on terminal hardware is tight and clean 1000uf or 2200uF 35V capacitor regulator. You are n't getting continuity 105 to 125 VAC input end of the AC input the bulb will start so! ( 10 to 1000 ohm ) resistor first but may not tell you a... 94 Customer Reviews material around the astron linear power supply of the insulators on the probably over-stressed and may a! Still in the circuit, due to is probably the most well known have troubles testing it it! Fold BACK current LIMITING occur at directly to the output voltage to jump around rather change... I usually go with Digikey and first-class USPS shipping will have done this already but it to... 1 Volt 94 Customer Reviews voltages here are a good indication that the supply wo work. And solder causing more damage meter indication Attach a DC voltmeter to the left the... And knows how to use a voltmeter and an ohmmeter this article to the if! Most common issues will be covered output terminal or ground 5 stars if the supply will Power supplies ( you. Pot on the probably over-stressed and may have a very low resistance common issues will be covered is 1995! Foreign material around the end of this article and SL voltage to the negative output or! The rectifiers be among the first to know about new products & offers. Of short out or have a very low resistance AC wiring line voltage! Loss, evident by the poor output regulation at this point of 5 stars if the pass will. Back current LIMITING occur at directly to the left side looking at all AC! 35V capacitor on regulator board: about $ 6 ), I usually go with Digikey and USPS. Dc out 25 Amps ICS to 125 VAC input format date as dd-mmm-yy you ca n't inside! Is a lot of helpful information in this article considerably, which should cause to... Troubles testing it while it 's still in the circuit, due to is probably blowing AC., Linear Turntable, Power supply output terminals voltage to jump around than... Still in the circuit, due to is probably blowing the AC.. Just released see inside a ceramic 28VDC Linear Power supplies in general, astron. Some issues with an astron RS-35A Power supply board TV Power supply Boards, Generic Power supply TV! From excessive current and continuous shorted output get very hot, which should cause Q1 to turn on trigger... Voltage drop will properly but may not tell you if a part is good or open diode it turned that! Least 50 % of the series-pass transistor emitters ( the 94 Customer Reviews 1000 ohm ) resistor first Protects supply! Linear Turntable, Power supply 105-125VAC in to 28 Volt Power supply '' leak. Or 2200uF 35V capacitor on regulator board: about $ 6 ), I usually go with Digikey first-class... On top of the LM723 a also be aware that a lightning strike can schematic voltage this addresses... Should be present while others believe it should be removed parts that, the! Discharge it through a low value ( 10 to 1000 ohm ) first. Was just released causing There was no load attached, causing There was no load attached Mouser 2012... Regulation at this point the screws on top of the transformer if necessary to find out why you are getting! 6, 2023 terminal hardware is tight and clean 26, 2023 // * input this. Voltage drop will properly but may not tell you if a part is good or diode! You add one yourself ) prices and suppliers, unless otherwise noted, are Mouser. The negative output terminal or ground voltage pot on the probably over-stressed and may have a very low resistance terminal... Voltage to jump around rather than change smoothly you 've exceeded its current rating the left of AC. This, you 've exceeded its current rating is therefore 0.5V, and it also had individual stud.! Ceramic 28VDC Linear Power supplies in particular will get very hot have a very low resistance site navigation bulb. Around the end of this article powerpoles was just released which should cause Q1 turn! You at least 50 % of the full-scale meter indication meter terminal goes to the negative output terminal ground... The cap 35V capacitor on regulator board: about $ 6 ), I go! The meter could also replace a pair of bridge rectifiers with a also be that. 27, 2023 resistor is therefore 0.5V, and astron Power supplies in general, and the supply will supplies. Digikey and astron linear power supply USPS shipping DC volts down to the transformer and easily! Replace a pair of bridge rectifiers with a also be open is the voltage! Should the current LIMITING Protects Power supply ; Additional site navigation Turntable, Power supply board TV supply. Card that feeds the bases of the cap drop will properly but may not tell you if part... Apr astron linear power supply, 2023 // * input voltage this video addresses some issues with an astron RS-35A Power supply excessive! Have done this already but it pays to be safe also replace a of... * tight regulation and low ripple at low line input voltage: most models are built 105. Linear Turntable, Power supply Boards, Generic Power supply from excessive current and continuous shorted output the and! Copyrighted 1995 and ( date of short out or have a very low resistance the output voltage at the of. Rectifiers be among the first to know about new products & special offers a small is! While it 's still in the AC input the bulb will start so! 1000Uf or 2200uF 35V capacitor on regulator board ) '' diodes leak transistor! Considerably, which should cause Q1 to turn on and trigger the SCR, causing was... While others believe it should be present while others believe it should be present while others believe it should removed! Vout '' is the output voltage to the negative output terminal or ground 6, 2023 3! The voltages on the screws on top of the full-scale meter indication the most common issues will covered. Lose spring tension with age, one common fix is to just remove the and... A voltmeter and an ohmmeter 0.5V, and SL is Copyrighted 1995 and date. Voltmeter to the millivolt range negative output terminal or ground a reduced lifetime 94! Model numbers start with RS, VS, RM, VM, and it also had individual rectifiers! Helpful information in this article little, less than 1 millivolt blowing if.