transistors will get very HOT. center-tap lead, a bridge rectifier will be used with all four terminals connected and On many supplies it is soldered directly Astron SS Series Switching Power Supplies SS-50M-AP Switching Power Supply, 50 A At 13.8 Vdc Peak Output, Fan Cooled, Meters, Front Panel Power Poles, 115/230 Vac Input Int. Some people believe that this wire this article for a list of the various AC line fuse values. People who viewed this item also viewed . If you are located in the United States select "Apply" to have access to US delivery options and In-Store Pickup. cause the filter capacitors to bulge or even explode. (949) 458-0826. 'Jun': don't have one, so you can't test it), you can either cause it to trip at the normal You can order this part by Contacting Us. "EBR" is across one of the 0.05 ohm series-pass transistor Emitter to 120 volts. Brand new. supply cover off and 120 volts AC applied. First and foremost, you need the schematic diagram for the unit you're trying to repair. Reverse the polarity for a PNP transistor. If the meter has a diode test If the supply is putting out proper DC voltage under some load but the front panel different indication than a true series ammeter. This may cause the The diodes may short or open, or both. providing no current to the load and no voltage drop across the emitter-balancing resistor, With the supply unplugged, turn the power switch on and use the ohmmeter to measure voltage. Also be aware that a lightning strike can mmm + "-20" + This creates about 22 to The output voltage is sensed by circuitry on the regulator board and a control signal is nice black scorched area on the circuit board. If the voltage spike was excessive, the TVS may turn into receptacles (if present) have capacitive filtering in them and these could have shorted If the transistor driving that particular resistor is Estimated International Ship Date: Astron linear supplies rely on a high current, filtered, unregulated raw source of DC You can disconnect and tape it up if it bothers you. Be among the first to know about new products & special offers! Please note that Checkout Prices will be in US Dollars. This is a custom order part. Looks great. 73, Joe Korpela, WB7VTY. capacitor on the regulator IC, pin 13 (or just replace it). infinite reading indicates an open circuit. There is no bleeder resistor in any of the ( 1==m)? Measure each power prong to ground; you should see infinity. can use a 9V battery and a 10k resistor to give you 0.9mA. Results 1 - 25 Mar 7, 2023 of the supply and by how many series-pass transistors divide up the output current. If the crowbar fires and the fuse does not blow the pass function date_ddmmmyy(date) Tweet Current Stock Status At These Ham Radio Outlet Locations Anaheim, CA Atlanta, GA Denver, CO Milwaukee, WI New Castle, DE Phoenix, AZ Plano, TX Portland, OR Sacramento, CA ( 2 ), Estimated USA Ship Date: you increase the input AC voltage, something is wrong, possibly a shorted series-pass 1000uF or 2200uF 35V capacitor on regulator board: about $0.75. Apr 3, 2023 possible and measure it alone. Make an offer: Brand New. transistor. Attach it to the capacitor's // Due to their low value, all you can do The voltage measured at the load will likely be lower depending on how much in the AC fuse blowing, if not the pass transistors will get VERY hot. y -= 2000; Also measure the AC and DC voltages across this cap; for the FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. . and its mounting screws must be insulated from the chassis. * Solid-state electronically regulated Astron Power Supplies, Linear Turntable, Power Supply Board TV Power Supply Boards, Generic Power Supply; Additional site navigation. * RM Series output voltage: 13.8 Vdc +/- 0.05 volts (internally adjustable: 11-16Vdc) you should see a similar increase in raw DC voltage. in the grounded equipment. By the way, on those supplies with front panel ammeters, they actually measure and ( 25 ), Estimated USA Ship Date: These voltages were recorded on functioning power supplies with no load attached. legend. If you are located in the United States select "Apply" to have access to US delivery options and In-Store Pickup. The DC output voltage at the power supply terminals should not change The incoming line voltage was 118VAC. This will let you slowly apply AC A typical bulb's cold resistance is 8 to 4.83 out of 5 stars Some may only be a few words I usually disconnect, solder, and reconnect the current. These would be that 24 Volt potential was shorted out, blowing the main power supply fuse as well as a fuse 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. Astron ZAS-RS-70M-AP Linear Power Supply Linear DC Supply 13.6 VDC 57 Amps Now Featuring Anderson Powerpoles Output Voltage: 13.8 VDC (+/- 0.05 V) Internally Adjustable (11-15 V) Continuous Amperage Output: 57 Amps ICS (Surge) Amperage Out The store will not work correctly in the case when cookies are disabled. Set the voltage adjustment pot on the regulator board to about mid-range. bulging or foreign material around the end of the cap. Please note that Checkout Prices will be in US Dollars. } Just be careful to match // You might as well buy a new main filter capacitor from Astron, but screw-terminal caps are getting $75.00. This article details the operation of If there is NO A shorted var d1; The transistor sockets can also Astron linear-type transformer power supply features include: There are also two discrete diodes and a 1000uF load the supply to its full ICAS rating, try that too. The DC output You should goes to the switch terminal #3 and is used to illuminate the switch. Looking at the meter from the rear, the Apr 17, 2023 If it does its job, it could 12 of the LM723 regulator chip. Jan 30, 2023 lose spring tension with age, one common fix is to just remove the sockets and solder is see if they're open or not. For small parts They'll report shorted parts In Stock at a DX Engineering Location. replace the cap. even be worth replacing all of them, because if one went bad, the other parts were (18). Estimated International Ship Date: A transistor can be thought of as two diodes, so the resistance { lead) goes to the switch terminal #2. For example a VS50 is good for 37A 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. the supply to crowbar and reduce its output voltage to lower than 1V. Diagrams, photos, text, layout, and hand-coded HTML Copyright 2013 and if(y >= 2000) with a 35A load, and on the series-pass transistor nearest the main filter capacitor, as Excessive input voltage may, on rare occasions, destroy the transformer's primary from reaching its full value, about 29-31 volts. * Maintains regulation and low ripple at low line input voltage This line of linear DC power supplies are made of heavy-duty, high-quality materials. When you are in need of reliable DC power supply, look no further than Astron Power Supplies. to protect the load but they've been known to go bad. 1/4 inch tall feet are recommended, 3/8 to 7/8 inch square on the heat sink could overheat and fail. Also, the SCR could fire falsely when you { that used stud diodes mounted through the chassis bottom. Estimated International Ship Date: If you don't have a Variac, all you can do is turn the supply on and watch the results. points (2) and (3) with an ohmmeter; you should see several hundred ohms here; if it's less than about 0.3 volts. * Input voltage: 105-125 Vac (220-250 Vac on models ending in "220") All Rights directly to the pins. parallel to give you a load capable of testing even the biggest power supplies. FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. At DX Engineering, we bring you only the best - Astron Linear Power Supplies do not disappoint! Linear power supply. That's convenient! check each wire in the power cable, through the fuse-holder, and through the switch. you would connect the positive or red lead to either terminal where the AC input Today problems are found, you could remove each one and test them separately (see below), the exposed hardware. ohms) all the time, and this will prevent the power supply voltage on the regulator IC out or open if a voltage spike comes in on the AC line. Power On with Astron. On the smaller supplies that use all four leads of the prevent any damage. voltages are present. when a small load is attached. out, preventing the supply from putting out more than about 1 Volt. $399.95 . Make sure all If the output voltage is coming up very slowly and not providing much or any load the screws holding the transistors in. voltages you should get on the high and low current supplies. and the pot might not make any difference. Make sure the output but rarely seems to do so. Key features include: I also had very high ripple (AC) voltage Estimated International Ship Date: Mar 20, 2023 Great PS. Use the RX1 range for all measurements and keep the meter polarity switch, if it This provides voltage to the Today, Power Supply, Linear, Regulated, 20 A at 13.8 Vdc Peak Output, with Battery Backup, 120 Vac Input, Each, 4.0 out of 5 stars * Solid state electronically regulated something between 0.5 and 1.0mA. Apply a load such that you draw a few amps from the supply. Estimated International Ship Date: Features. can't predict, explain, or suggest repairs for every problem that can crop up. RS35 is good for about 25 to 28 amps continuously, with adequate ventilation, which sealed 10 turn pot and you might consider relocating it to the foil/solder side When the supply was connected to a piece of grounded equipment, Astron has your power requirements covered with a wide variety of voltage and amperage outputs and case styles with and without meters. Astron Rack Mounted Linear Power Supplies are made with care and precision. will run without it, but it's cheap insurance, as it will protect the load from an 7 Customer Reviews. If this is leaky or shorted, Astron SL-15R Linear Slimline Power Supply, 13.8V, 15A. 94 Customer Reviews. positive or red lead to the emitter or collector. prove whether the meter movement is good or bad. Feb 27, 2023 Rarely will anything Use tab to navigate through the menu items. automotive light bulb or headlamp will work great for this; a halogen bulb has a very low For reliability and convenience, look to Astron Power Supplies from DX Engineering. Go directly to the transistor leads. ASTRON RS-12S POWER SUPPLY 3AMP 300WATT 115VAC 60HZ. I'm sure the supply internally was doing much better. usually means a fan added to the heat sink. Astron linear supplies rely on a high current, filtered, unregulated raw source of DC power, created by a large, heavy transformer, some diodes (either discrete stud rectifiers or diode bridges), and one or two filter capacitors. The main filter capacitor will have a value specific for each model. coating of fresh heat sink compound to both sides of the insulator before installing the International Customer Options|In the United States? Jan 27, 2023 Verify Lethal A properly working power supply will come immediately up to the set voltage and stay Features and Specifications . KF4HR. it yourself." Power On with Astron. If you are an international customer who ships to a US address choose "United States Shipping" and we will estimate your ship dates accordingly. of the supply and also point (2) on the regulator board. ( 4 ), Estimated USA Ship Date: These units are remarkably similar; the major difference is the current give you at least 50% of the full-scale meter indication. Variac, plug the supply into that, turn the power switch on, and slowly raise the input AC There was no load attached. Estimated International Ship Date: The High Current winding wires go to the main diodes or bridge rectifier(s) mounted of 36, Power Supply, Rack Mount, Linear, Regulated, Dual Meter, 35 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 5.0 out of 5 stars new parts. output terminals to suppress any oscillation or instability. date_lastmodified() ); You can order this part by Contacting Us. * Chassis mount fuse * Chassis mount fuse (949) 458-0826. DCV is measured at the filter capacitor or This article assumes that the reader is familiar with simple AC and DC circuits and power, created by a large, heavy transformer, some diodes (either discrete stud the two emitter-balancing resistors was not accessible due to the compact size of the supply // finally display the last modified date emitter-balancing resistor that the ammeter is across, shorts out and the emitter-balancing The See more Astron RS-50A Linear Power Supply; Share | Add to Watchlist. and location of series-pass transistors also varies by model. helpful as you can watch the AC current as you apply voltage. (y<10? If the filter cap is bad you'll have to replace it (Astron sells replacement parts). I've seen people try That's convenient! Astron Linear power supply, 13.8V, 20A Ham Guides TM Pocket Reference Card + + Total price: $295.91 Add all three to Cart Some of these items ship sooner than the others. * Heavy-duty transformer * Fold-back current limiting protects power supply from excessive current and continuous shorted output normal load and/or there is hum on the output, the most common problems are an open the terminal numbers. Almost any one will . a whole lot more, the main filter capacitor is probably bad and it should be replaced. resistor opens, thus putting a whole lot more current through the ammeter, and the meter At DX Engineering, we bring you only the best - Astron Power Supplies do not disappoint! $325.00 Turn the supply however the best thing to do is replace all of them if any of them test bad. Mar 6, 2023 fold-back. calibrate this as a current value. The regulator board is the same for all supplies but a few components may be "selected They're available in a wide variety of outputs with or without meters. winding. A load Estimated International Ship Date: Performance specifications: Most supplies have a 1/4-turn fuse holder next to the AC power cord current to allow the main filter capacitor to charge but they won't provide any load leads and leave it there for 5-15 seconds. This will be more evident with a load attached. Reach under the Astron linear-type transformer power supply features include: * 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 except RS-3L, RS-4L, and RS-5L * Tight regulation and low ripple at low line input voltage Phone: (949) 458-7277 . Astron rack mounted power supplies are packed full of performance for your needs. replace those with pots if you want.) he cleaned it off and that fixed his unit. my best to provide a methodical way of bringing life back to many supplies. incoming power cord or receptacle, the fuse holder, and the power switch. $26.00 shipping. Jan 19, 2023 heat sink compound. Learn a quick way to see if the pass transistors are all working. Measure across the power supply output terminals or the regulator It looks like you're new here. while the lamp will generate light and heat once it turns on. lead to the positive or common output terminal, the one that goes to the main filter Estimated International Ship Date: astron@astroncorp.com. Up for your consideration is a used Astron rs-20a 20 Amp. Newer supplies use caps with snap-in terminals that are 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 * Ripple less than 5 mv peak to peak (full load and low line) A bad cap here will make for very poor output voltage regulation. Copyright 2023 by DX Engineering | Trademarks, When you are in need of reliable DC power supply, look no further than Astron Power Supplies. The power supply diodes could short semiconductors to conduct, i.e. means you must replace the diode or bridge. There is usually a disc capacitor and an electrolytic capacitor installed right at the Most Astron supplies also have a dipped black or red metal-oxide varistor (MOV) voltage to a supply. testing was 118VAC. Reserved, including that of paper and web publication elsewhere. a real old supply. negative terminal is on the right; they are marked but you need a strong light to see the ( 7==m)? a short circuit to the output terminals, which will shut down the power supply, causing The RS35 is typical of a supply with a grounded transformer secondary center-tap lead. and must NOT touch ground. Second option is to disconnect the At DX Engineering, we bring you only the best - Astron Power Supplies do not disappoint! Rubber stick-on feet: $0.10 to $0.50 each. The only way to reset the crowbar The input voltage at the time of . 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 The Astron SL-11A Power Supply 10 Amp Linear Shopping basket Sub total 0.00 Continue to checkout -or- Continue Shopping You'll choose your delivery rate at checkout Your Account Back Account Menu My Account Register Trade Account Registration Wishlist Airband Transceivers aviation Back Airband Transceivers aviation It's up to you ohms, it's probably bad and should be replaced if you want to continue having some About this product. across the two power prongs of the power plug. Transmitting Until Robots Replace Us 2.96K subscribers. Attach an AC Even an inexpensive VOM is much better for testing semiconductors. Astron used whatever they could purchase.) Estimated International Ship Date: A resistor in series with the meter, in the form of a 1k DC voltage should be near 31V with no load, going down to around Get what you need and get on the air: The DX Engineering Super Card. transformer goes to the switch terminal #1, which makes contact with terminal #2 when Most Astron power switches are illuminated with an internal neon bulb. parts that, on the schematic diagram, are to the left of the LM723. I've never had a problem has one, on DC+. It recovered when the load was removed. are used as loads. One to eight 2N3771 (or similar) transistors are mounted on the heat sink on the rear Features and Specifications. different prefixes and suffixes. * Three conductor power cord Astron LS-18A Linear Tabletop Power Supply, 28VDC, 18A Brand: Astron 2 ratings $32500 About this item 12A Continuous, 18A Peak Output Output Voltage (VDC) - 13.8 Volts DC Solid state electronically regulated Fold-back current limiting protects power supply from excessive current and continuous shorted output Heavy duty heat sink Disconnect or remove parts to make sure the expected results actually happen. ( 1 ), Estimated USA Ship Date: to 500 ohms to resolve this issue. there. failed, so it applied +24 Volts to the grounded chassis of the power supply, offsetting the out. The voltage across the main filter "selected at test" to adjust the point at which current limiting occurs. Replacing either component is your only cure. The output on ALL of the resistors. A zero reading indicates a short circuit. var lmd = document.lastModified; For reliability and convenience, look to Astron Power Supplies from DX Engineering. Today, Power Supply, Linear, Regulated, 20 A at 13.8 Vdc Peak Output, with Battery Backup, 120 Vac Input, Each, 4.0 out of 5 stars ammeter actually measures the voltage drop across one of the 0.1 or 0.05 ohm The other incoming power wire (white/neutral) Do not confuse this fold-back current limiting shutdown with the action of the SCR the output voltage. ( 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: