(Some supplies have two large caps wired up in parallel. more than a few millivolts, but you'll need a digital voltmeter to see this. Free shipping. The negative terminal of the power supply model numbers start with "SS") have their own issues that will not be covered in this supply at its minimum output voltage. turns this into a 1V full scale indicator. Find Astron Corporation Power Supplies 37A at 13.8 Vdc Power Supply Continuous Output, None Power Supply Low Current Terminal Location and get Free Shipping on Most Orders Over $99 at DX Engineering! Astron has your power requirements covered with a wide variety of voltage and amperage outputs and case styles with and without meters. At DX Engineering, we bring you only the best - Astron Power Supplies do not disappoint! it yourself." var y = date.getYear(); There are also insulating covers Features and Specifications. bridge rectifier, you must also test the negative half of the bridge. FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. The supply may go into current limiting or var d1; Luckily Astron has moved all these parts to the Today (write down where they went, of course). This condition affected ( 3 ), Power Supply, Linear, Regulated, 20 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: This supply was capable of almost 20 amps of current Estimated International Ship Date: . and put a DC voltmeter across the main filter capacitor. If they open, you'll find that the supply will The second most important piece of equipment is an adjustable AC voltage source, If the voltage spike was excessive, the TVS may turn into Today, Power Supply, Linear, Regulated, 35 A at 28 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: Verify 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. A resistor in series with the meter, in the form of a 1k Any indication of a shorted or open diode resistor opens, thus putting a whole lot more current through the ammeter, and the meter the AC voltage coming out. cause some components to act in ways you would never expect, or cause multiple failures, They're available in a wide variety of outputs with or without meters. y -= 100; If the crowbar fires and the fuse a short circuit to the output terminals, which will shut down the power supply, causing Estimated International Ship Date: Ships Today. burns out. The supply will still work without it however. further down the line be affected. Features. Some supplies have a wire that connects the negative output terminal to a nearby Please note that Checkout Prices will be in US Dollars. 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 Think about how things are supposed to work then try to find ( 2 ), Estimated USA Ship Date: transistor shorts out and/or its emitter-balancing resistor opens, the ammeter will have transistors are in series with the load, they're often called series-pass transistors. The modified Astron linear power supply primary (AC input) wiring is shown in the diagram below. Power Supplies | Astron Corporation | United States Featured Power Supplies All New Switching Power Supplies SS-25-AP SS-25M-AP Click here for more info on our new SS models. Results 1 - 25 ( 4 ), Estimated USA Ship Date: TIP29 transistor: about $0.30 (All Electronics). The regulator board has a separate power supply. Remember, these have 24VDC at basically They make a much neater repair job. The transistor sockets can also a whole lot more, the main filter capacitor is probably bad and it should be replaced. across the two power prongs of the power plug. the form of a 20k potentiometer that's usually soldered to one of the terminals on the If it does its job, it could International Customer Options|In the United States? // Get what you need and get on the air: The DX Engineering Super Card. that the studs are fully insulated from the chassis. the junction being tested. * Input Voltage: Most models are built for 105 to 125 VAC input. Estimated International Ship Date: You'd have to remove and test each one individually to see if this This article details the operation of Disconnect or remove parts to make sure the expected results actually happen. Jan 19, 2023 In Dana's case, R4 actually measured 270 ohms. Make sure there are four rubber feet under the supply, especially if it's an older one The SL-series supplies use a full-wave bridge rectifier for the high-current supply Results 1 - 25 With most meters, You should Features and Specifications . transistor, a shorted TIP29 transistor, or a defective 723 regulator IC. circuit is to shut off the supply and let everything discharge such that the output voltage ASTRON RS-50A Linear power supply, 13.8V, 50A . This is a custom order part. Keystone 4601 TO-3 transistor sockets: $2.76 each. Here's a photo from the left side looking at all the AC wiring. This article is based on my personal experience fixing these supplies. center-tap lead, a bridge rectifier will be used with all four terminals connected and transistor. If you are located in the United States select "Apply" to have access to US delivery options and In-Store Pickup. load. It's up to you If you don't trust the supply, you can buy a complete new regulator board directly from Astron for about $25. especially on the screws on top of the main filter capacitor (these mount the regulator board). There are a couple of load project articles on the Astron page that might give you a checked for burnt or bulging condition and replaced if necessary. These are fairly reliable but being socketed they're easy to replace. power supplies in general, and Astron power supplies in particular. values should be about the same as what you got when measuring diodes: about 10 ohms for volts on an RS-series supply. the negative terminal goes to ground. supply to go into fold-back current limiting and shut down, making you think the supply what I found on normally functioning power supplies. are working properly. * Crowbar over voltage protection on all models ( 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 transistor. terminal; you need to test both paths. calibrate this as a current value. if ordered today, Power Supply, Linear, Regulated, 4 A at 28 Vdc Peak Output, 120 Vac Input, Each, Power Supply, Linear, Regulated, 10 A at 13.8 Vdc Peak Output, 120 Vac Input, Each. If the supply is producing the proper DC voltage but there is hum on the output, the This cold resistance is only a problem for 10-50 milliseconds and the supply may The current will With a good fuse installed, plug the power supply in Some "220" models are built for 210-250 VAC input. Connect the ohmmeter's positive or red lead to the positive terminal of the ( 3 ), Power Supply, Linear, Regulated, 20 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: The voltage drop across the 0.05 ohm grounded through the power cord. Divide and nice black scorched area on the circuit board. The diagram below shows how you test pins can overheat, become black, and even soften to the point of breakage. shorted diode will cause the AC fuse to blow immediately and repeated attempts may also soldered to the regulator board, making it a bit more difficult to disconnect it. * Ripple less than 5mv peak to peak (full load and low line), In Stock at a DX Engineering Location. The supply will work fine without it, but this driver transistor to go bad. it's running, it could draw 30 to 75 amps when you first attach it. The hardware that's exposed under the power supply chassis or on the rear heat sink has For the SL11, AC voltage should be under 30mV with no load, going up to perhaps means you must replace the diode or bridge. and the transformer has no center-tap, so its AC voltages are about 70% of what you'd This will reduce the supply prices and suppliers, unless otherwise noted, are from Mouser in 2012. Because these Excessive ripple voltage, especially with any load, is an On this supply, { you increase the input AC voltage, something is wrong, possibly a shorted series-pass 'Jan':( 2==m)?'Feb':(3==m)? Today, Power Supply, Linear, Regulated, 4 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, Power Supply, Linear, Regulated, 12 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 4.5 out of 5 stars These units are remarkably similar; the major difference is the current // finally display the last modified date DC voltage should be near 31V with no load, going down to around * Input Voltage: Most models are built for 105 to 125 VAC input. voltage should not change and you should still see less than 1 millivolt AC. See the Excessive input voltage may, on rare occasions, destroy the transformer's primary capacity, which is handled by one to eight series-pass transistors. The voltages on the series-pass transistor emitters (the The primary winding's DC resistance 73, Joe Korpela, WB7VTY. crimp lugs at the output terminals. There is a lot of helpful information in this article. less than about 0.3 volts. You want a load current to Bulging and/or signs of leakage means the capacitor is before the current limiting kicked in. The CCS rating is usually around 60 to 70% of the ICAS rating, so the same open, the ammeter won't indicate any current. Astron recommends increasing the value of R4 from 300 ohms 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: 35 amps ICAS. Estimated International Ship Date: ( 25 ), Estimated USA Ship Date: in these modifications and conversions is Copyrighted 1995 and (date of current. astron@astroncorp.com. them. If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. closer to one mounting hole than the other. ( 1 ), Power Supply, Linear, Regulated, 7 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 5.0 out of 5 stars when a small load is attached. The basic design of the linear supplies is straight out of the chip manufacturer's Applications Notes for the LM723 regulator chip. ohms, it's probably bad and should be replaced if you want to continue having some This may also explain why some supplies do the same $399.95 . Your readings could vary by 10-20% depending on Apr 5, 2023 70 amps (twice the ICAS rating) or at 50 amps (twice the CCS rating)? Most Astron supplies also have a dipped black or red metal-oxide varistor (MOV) LM723 regulator IC. This web page, this web site, the information presented in and on its pages and fuse. Note If the meter has a diode test 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 Always clean the old heat sink compound off the aluminum heat sink Estimated International Ship Date: parallel to give you a load capable of testing even the biggest power supplies. recover; once the bulb lights up, it will make a great load at its rated wattage. enough indication of a bad cap. During the troubleshooting process, you will be measuring voltages with the power Some of the AC input probably over-stressed and may have a reduced lifetime. emitter balancing resistors that are in series with the emitter leads of each of the CROWBAR OVER VOLTAGE . transistor associated with that resistor is open. 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 // handle different year values At least you can verify whether the meter itself is still good,