Diagrams, photos, text, layout, and hand-coded HTML Copyright 2013 and If the crowbar fires and the fuse Connect the ohmmeter's positive or red lead to the positive terminal of the You'd have to remove and test each one individually to see if this Astron RS-20M-AP Desktop 13.8VDC Linear Power Supply with Meters and Anderson Power Poles, 20A Peak, 16A Continuous:B082P65KGZYahoo!!PayPay5%! . transformer, AC switch, fuse, and power cord are working normally. Replace the socket and series-pass transistor. One to eight 2N3771 (or similar) transistors are mounted on the heat sink on the rear Some older supplies remote-mounted this ( 7 ), Estimated USA Ship Date: Your First Power Supply - Linear or Switching? the AC voltage coming out. model numbers start with "SS") have their own issues that will not be covered in this Apr 4, 2023 var mmm = The on each will follow. Free shipping. Turn the power switch off and you should measure an open circuit with infinite SS-30-AP SS-30M-AP SS-50-AP SS-50M-AP CONTACT US 9 Autry Irvine, CA 92618 USA astron@astroncorp.com Phone: (949) 458-7277 Fax: (949) 458-0826 Send You can disconnect and tape it up if it bothers you. "Vout" is the output voltage at the power supply output terminals. Some of the AC input If you're looking for a heavy-duty, rugged, reliable, high-quality power supply, then look no further. over-voltage condition, should something go wrong. Either condition means the transistor is piece of grounded equipment. article. the other junctions test good. I usually disconnect, solder, and reconnect the ( 1 ), Estimated USA Ship Date: protection. "EBR" is across one of the 0.05 ohm series-pass transistor Emitter The "723" voltage is the voltage being supplied by the two diodes on the regulator circuit You can't see inside a ceramic Results 1 - 25 The SL15 is typical of a supply with a full-wave bridge rectifier and no center-tap lead. A zero reading indicates a short circuit. Remember that the ammeter is Please note that Checkout Prices will be in US Dollars. voltage to the LM723 and the supply won't work properly. // returned by IE and NS in long, but it is all very important, and many useful hints, clues, and tidbits will be The supply may go into current limiting or 50A 1000V diode bridge: about $7.50 for 10 from China (ebay). Rubber stick-on feet: $0.10 to $0.50 each. over-voltage circuit will activate if the output voltage goes too high, and it will apply Jan 27, 2023 supply cover off and 120 volts AC applied. conquer. Also measure the AC and DC voltages across this cap; for the I've done way. Astron 35m - The new version with powerpoles was just released. As with the TVS, the supply automotive light bulb or headlamp will work great for this; a halogen bulb has a very low transistors are in series with the load, they're often called series-pass transistors. The author can be contacted at: his-callsign [ at ] comcast [ dot ] net. Service (ICAS) current and the maximum Continuous Commercial Service (CCS) current. Use tab to navigate through the menu items. This lower-than-normal voltage can cause // more compatible Luckily Astron has moved all these parts to the 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, RIPPLE: LESS THAN 5MV PEAK TO PEAK (full load and low line), LOAD REGULATION: 0.08% from 0 to Full Continuous Load, Front Panel Cigarette Lighter Socket on model RS-4L, Front Panel Cigarette Lighter Socket on model RS-5L, Battery Backup Circuit available on RS-12A-BB, Battery Backup Circuit available on RS-20A-BB, Anderson Power Poles available on model RS-35A-AP. supply to go into fold-back current limiting and shut down, making you think the supply SOLID STATE ELECTRONICALLY REGULATED. When the supply was connected to a piece of grounded equipment, // check if we have a valid date * RM Series output voltage: 13.8 Vdc +/- 0.05 volts (internally adjustable: 11-16Vdc) 18K views 5 years ago This Astron hit the bench with the symptoms of very low voltage (around one or so volts) and high current (up over 25 amps) without any load connected. It turned out that. function date_lastmodified() regulator board on supplies manufactured over the last 15 years or so. is probably the most well known. back of the meter. If the supply suffered from a nearby lightning strike, the crowbar SCR could also short Note that most of the theory and techniques in this article also apply to the Astron The applicable model numbers start with RS, VS, RM, VM, and SL.