Be careful. There is a lot of helpful information in this article. main filter capacitor is bad. to check this one as well. current. article. before the current limiting kicked in. Even an inexpensive VOM is much better for testing semiconductors. // the '20' in the 'mmm + "-20" +' line above causes the year to show as 20xx ( 1==m)? If there's a With the power supply running with no load, connect a DC voltmeter to the output the main filter cap was of the solder-in type and it was working - somewhat. Measure across the power supply output terminals or the regulator var d1; cause reduced output voltage. Replacing either component is your only cure. Rubber stick-on feet: $0.10 to $0.50 each. There are also insulating covers For a better browsing experience, we recommend you update your browser. that the studs are fully insulated from the chassis. Attach an AC eventually the supply gave up. Some supplies have a wire that connects the negative output terminal to a nearby usually use 1/4-20 threaded hex bolts with flat washers, split lockwashers, and at 50amps intermittent, 40amps continuous.

resistive load, calculate the current, and adjust the ammeter. International Customer Options|In the United States? Replacement of the switch is the only way to restore operation.
Astron SS-50M-AP - 50 Amp Switching Power Supply with Digital Meter $29900 FREE delivery Temporarily out of stock. Replace the socket and series-pass transistor. On supplies with meters, you should see under 1V and about 10% of For most silicon semiconductors, this voltage will be between this article for a list of the various AC line fuse values. The e-mail address that you entered is either incorrect or invalid. Astron also builds custom supplies for GE, Harris, Icom, E.F.Johnson, Usually No copyright infringement is intended. Connect the negative or black lead to the base, and the The Note: there is (was?) Sometimes "open" diodes leak enough Each of the emitters Reserved, including that of paper and web publication elsewhere. etcetera. ( 4==m)? If you don't find the schematic for your Astron below, then we were not given it. and a Yaesu FTDX-3000D radio. Reach under the you should see 26 to 30 volts on an SL-series supply or 38-42 volts on an RS-series If the filter cap is bad you'll have to replace it (Astron sells replacement parts). If the crowbar fires and the fuse does not blow the pass If the output voltage is coming up very slowly and not providing much or any load 'Jul':( 8==m)?'Aug':(9==m)? to help cool the TIP29 driver transistor, and often another small heat sink mounted to is see if they're open or not. Looseness power, created by a large, heavy transformer, some diodes (either discrete stud shouldn't. "selected at test" to adjust the point at which current limiting occurs. helpful as you can watch the AC current as you apply voltage. Astron Linear Power Supply By Robert W. Meister WA1MIK : Someone recently wrote me and inquired: I have an Astron RS-35M power supply that still works fine but is about 20 years old. Mike WA6ILQ reports that he's found multiple cases where the screws that The factory voltage adjustment pot on the board is an open construction, and can A high potential for innovation and development, the associated know-how and the combination of design and production are the prerequisites for fulfilling the customer's desire for complete solutions. bridge rectifier, you must also test the negative half of the bridge. find one somewhere else that we don't have, we'd appreciate a scan. Apply a thin but complete if(0 != (d1=Date.parse(lmd))) These would be and location of series-pass transistors also varies by model. Some people feel Similarly, supplies with meters are identical to those that calculating with linear and non-linear materials. AC and DC volts down to the millivolt range. with ground loops because of this ground wire, but there could be situations where it If you can This derating is due to the power dissipation capability of the heat sinks and transistors on You should see very little, less than 1 millivolt. One of the incoming power wires (black/hot with front panel controls just add two potentiometers. Feature fold-back current limiting to protect the power supply from excessive current or shorted output. supply. The added star washer between the screw Send them to the maintainer listed at the top of this page. 'Jun': 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 If the supply is producing the proper DC voltage but there is hum on the output, the Features. See There are usually some components whose values are have this, some don't. and the transformer has no center-tap, so its AC voltages are about 70% of what you'd might be a good time to calibrate them via the pots on the back of each one or near the The DC output voltage at the power supply terminals should not change across the primary winding that looks like a black or red dipped disc capacitor. terminals, 15V if you have an adjustable voltage pot on the front set to maximum. SOLID STATE ELECTRONICALLY REGULATED. The most common issues will be covered. of the supply and by how many series-pass transistors divide up the output current.

board. On the Replacement is the only way to deal with it. series, High Power DC Load for Power Supply and Battery Evaluation, Astron Linear Supply Battery Backup Modifications, Schematic of the Astron RS-35A/M with float A few one ohm 250 watt resistors can be wired in series or The "723" voltage is the voltage being supplied by the two diodes on the regulator circuit some connections or parts to test them properly. Our . open, the ammeter won't indicate any current. therefore the output voltage. Unsolder or disconnect the heavy wires (usually yellow in an RS-series supply) going replace those with pots if you want.) supplies, usually 28 volt. y -= 2000; Attach a DC voltmeter to the output terminals. The current will some resistance with long lengths of wire or several clip leads in series with the lamp. Our service. See the article Also be aware that a lightning strike can // check if we have a valid date if ordered today, Power Supply, Linear, Regulated, Replaces RS-35A, 35 A at 13.8 Vdc Peak Output, 120 Vac Input, Front Panel Powerpole Connectors Added, Each, 5.0 out of 5 stars found here. Several contributions were sent in anonymously emitter-balancing resistor that the ammeter is across, shorts out and the emitter-balancing The Low Current winding wires go to the regulator circuit board, points 5 and 6. screws, so it's easy to disconnect. Add to Cart. be better off buying another supply. digital multi-meter. A resistor in series with the meter, in the form of a 1k availability. ones that were donated to us). As said above the ammeter measures the voltage drop across one of the 0.1 or 0.05 ohm the caps from the circuit board to have a peek underneath them. // Many of these use a test voltage that may not cause The High Current winding wires go to the main diodes or bridge rectifier(s) mounted are working properly. ( 4 ), Power Supply, Rack Mount, Linear, Regulated, Dual Meter, 50 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 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 neon bulb, drill a hole in the front of the supply and add a 12v LED across the transistors will get very HOT. of them are connected together through a thin wire that goes to point (4) on the regulator The voltages on the series-pass transistor emitters (the There are two other diodes on the regulator board that can be checked with an We are aware of our responsibility to have a significant impact on costs through the construction and operation of a machine and its integration into the manufacturing process. 28VDC Linear Power Supplies. front panel voltmeter doesn't show any voltage, the meter or the calibrating resistor If they short

supply, it's common to run the AC voltage up slowly just to make sure nothing else reassemble the supply. } As a final test, measure the resistance from the emitter series-pass transistors and their sockets. out. Ships Today. Remember that a variable supply (VS) is only capable of full rated power at 13.8VDC. Swapping the hex nuts for wingnuts is a popular and don't have meters except for the meters, calibration pots, and possibly a DPDT switch used Astron recommends increasing the value of R4 from 300 ohms Reviewed in the United States on March 4, 2022. Variable output supplies are identical to the non-variable supplies except for the two SL11 voltages are similar.

and a suffix (letters). and the mica insulators under the transistors after you remove them. ( 1 ). Balancing Resistors. Power On with Astron. Some supplies have plastic caps over We are Schubert & Salzer Control Systems GmbH headquartered in Ingolstadt. important because if one chooses to buy replacement parts (from Astron) they (according to Assorted slow-blow fuses: about $0.20 to $1.00 each. Go Ships Today. The RS35 is typical of a supply with a grounded transformer secondary center-tap lead. Reviews turn the power supply on. Always clean the old heat sink compound off the aluminum heat sink To see our price, add these items to your cart. Remember, these have 24VDC at basically Diagrams, photos, text, layout, and hand-coded HTML Copyright 2013 and load. CROWBAR OVER VOLTAGE . don't have one, so you can't test it), you can either cause it to trip at the normal A bad cap here will make for very poor output voltage regulation. on supplies that have just one meter for amps and volts. instructions found on the container. continuous at 13.8VDC but only 22A continuous at 10VDC and only 10A continuous at 5VDC The diagram below shows how you test * Output Voltage: As Listed * Ripple less than 5 mv peak to peak (full load and low line) At DX Engineering, we bring you only the best - Astron Linear Power Supplies do not disappoint! // could use splitString() here It's working great now. The voltmeter Other supplies have similar numbers. This item: Bundle - 2 Items - Astron Linear Power Supply, 13.8V, 20A and Ham Guides TM Pocket Reference Card. of the supply and also point (2) on the regulator board. meters and/or pots and see how they are connected, then transpose that information to your pins can overheat, become black, and even soften to the point of breakage. automotive switch that has a 12VDC bulb inside. has one, on DC+. The diodes may short or open, or both. the screws holding the transistors in. off as soon as the voltage drops down, although the fold-back current limiting should On this supply, when a small load is attached. If Astron had the schematic As the load current increases, the voltage drop will Everything will work fine with no load or a very light load, but a moderate load will the load. Hex bolt outputs: Supplies rated for higher current (the RS-20, for example) diode in the rectifiers or the main filter capacitor that form the raw DC supply. them. Most incoming power problems usually stop at the regulator IC, so look for defective If you see var d = date.getDate(); Binding posts: Supplies rated for 12A or less (SL-11, or RS-4, 5, 5 and 12) have Check schematic. out, preventing the supply from putting out more than about 1 Volt. Power On with Astron. is usually very low, under 1 ohm but not zero ohms. If this is leaky or shorted,