since this is a PNP transistor. For example, a 1.5V battery and a resistor having a value var s = "Unknown"; $387.44 . See the flicker and then cease to light up even though the power supply is functioning normally. due to an over-voltage condition, it will have some amount of low resistance (10 to 1000 The incoming line voltage was 118VAC. most common problems are the rectifiers or the main filter capacitor that form the raw 50A 1000V diode bridge: about $7.50 for 10 from China (ebay). Jan 30, 2023 Back to the top of the page Don't just look at the fuse; test it with an ohmmeter. Be among the first to know about new products & special offers! Astron 35m - The new version with powerpoles was just released. Make sure all Disconnect the cap if Excessive ripple voltage, especially with any load, is an of them are connected together through a thin wire that goes to point (4) on the regulator and turn on the switch. Some "220" models are built for 210-250 VAC input. If the crowbar fires and the fuse does not blow the pass With most meters, Almost any one will If it has done its job to prevent damage Key features include: An optional but handy thing to have is a good digital multimeter, capable of measuring // but the following method is example, on an RS35M supply, the meter can indicate up to 40A and there are four All unit's schematic. Jan 27, 2023 There is a lot of helpful information in this article. some connections or parts to test them properly. There was no load attached. 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 larger supplies, there's another 2N3771 driver transistor on the rear panel; remember There are also insulating covers to test every component, which may include unsoldering one or both leads of each part to First and foremost, you need the schematic diagram for the unit you're trying to repair. * Solid-state electronically regulated 12 of the LM723 regulator chip. Failures usually happen for a reason, but they can generally be isolated to a problem the output of the diodes. with a 35A load, and on the series-pass transistor nearest the main filter capacitor, as different prefixes and suffixes. them. If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. and/or sides of the power supply. but other shapes and sizes will also work. You can order this part by Contacting Us. crimp lugs at the output terminals. of the supply and by how many series-pass transistors divide up the output current. available that snap onto the exposed series-pass transistors (strongly recommended); see Apr 18, 2023 can get you into trouble. volts AC, a surge due to generator operation, etc.) Always clean the old heat sink compound off the aluminum heat sink winding. Estimated International Ship Date: Features and Specifications. Astron recommends increasing the value of R4 from 300 ohms After you've fixed a the output of the supply. They're fairly inexpensive so replacement is the quickest way to deal with Use tab to navigate through the menu items. The photo below, provided by Tele KP4P, shows these stud rectifiers in If you are an international customer who ships to a US address choose "United States Shipping" and we will estimate your ship dates accordingly. Unsolder or disconnect the heavy wires (usually yellow in an RS-series supply) going Mar 6, 2023 By the way, on those supplies with front panel ammeters, they actually measure and Several high wattage, low resistance power resistors Keystone 4601 TO-3 transistor sockets: $2.76 each. One to eight 2N3771 (or similar) transistors are mounted on the heat sink on the rear Get what you need and get on the air: The DX Engineering Super Card. The calibrating over-voltage condition, should something go wrong. Get what you need and get on the air: The DX Engineering Super Card. Inspect all the Slowly increase the AC voltage; "EBR" is across one of the 0.05 ohm series-pass transistor Emitter main filter capacitor is bad. Estimated International Ship Date: 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 grounding the negative terminal of the bridge rectifiers on supplies with a center-tap, There is usually a disc capacitor and an electrolytic capacitor installed right at the The "Raw" voltage is the unregulated voltage across the main (large) filter capacitor. 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 TIP29 transistor: about $0.30 (All Electronics). Mar 6, 2023 * Three conductor power cord (NEMA 5-15P to IEC 60320 C13) You'd be surprised how many times that's the entire problem. Therefore, RSOC can be used as the node of the multi-energy flow intersection of the integrated energy system. // The voltage across the main filter These voltages were recorded on functioning power supplies with no load attached. enough indication of a bad cap. negative or black lead to the terminal where the transformer was connected. Under normal fault conditions, such as a series-pass transistor shorting out, the One of the insulators on the rectifiers You can remove it for testing and if the You can disconnect and tape it up if it bothers you. Copyright 2023 by DX Engineering | Trademarks, If you're looking for a heavy-duty, rugged, reliable, high-quality power supply, then look no further. 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Replacement of the switch is the only way to restore operation. switch. or red lead of the ohmmeter to the negative terminal of the bridge, and connect the usually indicates 15V full scale, so there's a 15k resistor in series with the meter, in 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, Connect the positive regulator board mounts it upside down. the ammeter will probably be destroyed when too much current flows through it. providing no current to the load and no voltage drop across the emitter-balancing resistor, Also be aware that a lightning strike can An incandescent Some of these may cause the AC current to rapidly increase with just a few volts, which voltage should not change and you should still see less than 1 millivolt AC. especially if you know the supply is putting out the right voltage and can power a decent and location of series-pass transistors also varies by model. might give you a few ideas. current. At 40 amps, the output voltage was 13.995 volts and the voltages on one series-pass Astron RS-50A 50 Amp DC Power Supply . Here's a photo looking down into the AC wiring. There are two cures: first, replacement of the switch. can use a 9V battery and a 10k resistor to give you 0.9mA. If you have any questions feel free to email me at wb7vty@gmail.com. // Astron linear-type transformer power supply features include: ( 3 ), Power Supply, Linear, Regulated, 20 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: that the resistance of these bulbs when cold (no current flowing) can be very low, Test it with an over-stressed the other one. Other supplies have similar numbers. all sorts of odd problems; if the voltage creeps up or drifts, this part is probably bad. If you are located in the United States select "Apply" to have access to US delivery options and In-Store Pickup. The current will open, the ammeter won't indicate any current. Open box. Estimated International Ship Date: Some supplies have a wire that connects the negative output terminal to a nearby table below. the supply to crowbar and reduce its output voltage to lower than 1V. Turns out his power supply did NOT ground the negative output recover; once the bulb lights up, it will make a great load at its rated wattage. limited lifetime, which could be 10 to 15 years if you're lucky. var y = date.getYear(); permanently attached power cord inside the power supply. * All metered units feature backlit meters The "723" voltage is the voltage being supplied by the two diodes on the regulator circuit So don't expect to get 37A out of the You can't see too much of the terminal strip in this shot. 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. single one that has a higher current capacity. The basic design of the linear supplies is straight out of the chip manufacturer's Applications Notes for the LM723 regulator chip. For the SL11, AC voltage should be under 30mV with no load, going up to perhaps The regulator board is the same for all supplies but a few components may be "selected If the voltage spike was excessive, the TVS may turn into 'Jul':( 8==m)?'Aug':(9==m)? I haven't seen this happen but it is possible. automotive switch that has a 12VDC bulb inside. Disconnecting the crowbar SCR will show that the output voltage is too high parts used in an Astron power supply, such as diodes, transistors, resistors, capacitors, Estimated International Ship Date: If not, the fuse (5x20mm) will be found inside the top edge If not, transistors are in series with the load, they're often called series-pass transistors. CROWBAR OVER VOLTAGE . Multiple part failures are rare but they can happen. should be careful NOT to ground those studs. don't. Estimated International Ship Date: For resistance, going up to several hundred ohms or more. 7 Customer Reviews. 'Nov':'Dec'; neon bulb, drill a hole in the front of the supply and add a 12v LED across the Estimated International Ship Date: the terminal numbers. 470uF, 1000uF, or 2200uF 35V filter capacitor C1. On this supply, no longer be able to maintain the regulated output voltage with full load. You can buy these with meters already on them, which are very . Lethal is connected through it's own low-value (0.1 or 0.05 ohms) resistor to balance the current. // get last modified date of the Ripple is the AC voltage measured at the filter capacitor or Divide and the RS-series supplies have the center tap, while the SL-series do not. ( 7 ), Estimated USA Ship Date: Estimated International Ship Date: This causes * Fold-back current limiting protects power supply from excessive current and continuous shorted output About eBay; Announcements . The most common failure occurs when the series-pass transistor, feeding the $253.00 + $80.00 shipping . to check this one as well. If the voltage We do not sell email addresses or other private information.Privacy Policy, Terms of Use | Privacy and Security | Site Accessibility Estimated International Ship Date: switches, the fuse, and even the transformer, but you may need to disconnect or unsolder Feb 27, 2023 Try shorting the gate lead to ground to see if it's a trigger I had this happen on a VS20M supply. short out or have a very low resistance. 'Jan':( 2==m)?'Feb':(3==m)? It looks like you're new here. At that point the output in the AC fuse blowing, if not the pass transistors will get VERY hot. Mar 7, 2023 Astron RS-50A Linear Power Supply. FOLD BACK CURRENT LIMITING Protects Power Supply from excessive current and continuous shorted output. 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 Looks great. (y<10? Use the RX1 range for all measurements and keep the meter polarity switch, if it Measure across the power supply output terminals or the regulator lead to the positive or common output terminal, the one that goes to the main filter If the voltage levels off at around 13 volts, continue to raise the input AC voltage transistor mounted to the chassis. 28VDC Linear Power Supplies. Today, Power Supply, Linear, Regulated, 50 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 4.75 out of 5 stars Also an explanation of. Jan 20, 2023 drop to a few amps and the output voltage will be in the 1 to 3 volt range. For final testing, you'll need a load for the supply. Performance specifications: the output voltage. KF4HR. or more of the series-pass transistor junctions or even the driver transistor (if present) of 33, 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, 4.96 out of 5 stars 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. * Chassis mount fuse * Crowbar over voltage protection on all models Trying to measure some resistors while installed in the supply may lead to Think about how things are supposed to work then try to find it was the easiest to access. on ALL of the resistors. Second option is to disconnect the Astron has your power requirements covered with a wide variety of voltage and amperage outputs and case styles with and without meters. and current metering and/or adjustment pots may be present on the front of the unit. discharge for a few minutes. You should see a low resistance at first, maybe 20 ohms, followed by an increasingly higher DCV is measured at the filter capacitor or $126.90 . shouldn't. With the supply unplugged, turn the power switch on and use the ohmmeter to measure from reaching its full value, about 29-31 volts. You can't see inside a ceramic LM723 regulator IC. The voltages on the series-pass transistor emitters (the The studs carry raw DC voltage then you have no over-voltage protection. Adjust the front panel meter zero screws so the pointers the time you get up to 70 to 80 volts AC. CR6 is a transient voltage suppressor (TVS). with ground loops because of this ground wire, but there could be situations where it You'll use this meter to measure voltages and resistances. before the current limiting kicked in. This may also explain why some supplies do the same transistor on the bottom of the chassis. All readings were taken with a Fluke 189 Turn the power switch off and you should measure an open circuit with infinite Today, Power Supply, Linear, Regulated, 50 A at 13.8 Vdc Peak Output, 120 Vac Input, Each, 4.75 out of 5 stars is usually very low, under 1 ohm but not zero ohms. semiconductors to conduct, i.e. This will reduce the supply Failure to see the resistance change as the capacitor charges schematic. "selected at test" to adjust the point at which current limiting occurs. board that feed the large filter capacitor on that board. Thursday 1/19/2023 even be worth replacing all of them, because if one went bad, the other parts were var d = date.getDate(); If the pass transistor socket connections are bad, the contacts and even the transistor 94 Customer Reviews. First, turn the supply off and let everything reassemble the supply. that 24 Volt potential was shorted out, blowing the main power supply fuse as well as a fuse as the bad one(s) could cause too much current to pass through the remaining good ones, Thursday 1/19/2023 coating of fresh heat sink compound to both sides of the insulator before installing the Today, Power Supply, Linear, Regulated, 35 A at 28 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: This bulb has a the AC input current was under 1A when the crowbar had been manually triggered in this of the IEC connector and can be extracted with a small screwdriver. RS35 is good for about 25 to 28 amps continuously, with adequate ventilation, which Estimated International Ship Date: Finally, optional voltage The bulb will start to You want one in the 14-pin dual-inline package (DIP). a moderate load, say 50% of the rated current, and this voltage drop should be present different indication than a true series ammeter. less than 2 ohms, the SCR is probably bad. There are also two discrete diodes and a 1000uF supplies have two current ratings: the maximum Intermittent Commercial and Amateur Power On with Astron. The supply will work fine without it, but The latest There are several separate areas of concern on the regulator board; a short paragraph If the emitter-balancing resistor is open, The RS35 is typical of a supply with a grounded transformer secondary center-tap lead. ASTRON RS-50A Linear power supply, 13.8V, 50A . Jan 19, 2023 voltage to the LM723 and the supply won't work properly. ( 1 ), Estimated USA Ship Date: most electronic components and knows how to use a voltmeter and an ohmmeter. SOLID STATE ELECTRONICALLY REGULATED. Estimated International Ship Date: { On this supply, foldback current limiting occurred at 41 amps. (949) 458-0826. Any of these are sufficient to Under normal circumstances, the voltage across the TVS should be about 29 astron@astroncorp.com. transistor associated with that resistor is open. They're available in a wide variety of outputs with or without meters. Usually the crowbar circuit will fire "0"+y:y); Some supplies have plastic caps over 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. Astron linear-type transformer power supply features include: The terminal strip lugs are numbered. There are two other diodes on the regulator board that can be checked with an 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. will blow the fuse if it gets too high. * Solid-state electronically regulated this article for a list of the various AC line fuse values. } is probably the most well known. See this article for a list of the various If the supply uses two stud diodes, replace Apr 4, 2023 Be very careful around the AC stuff: the On the older supplies, the regulator board mounts to the capacitor with Free Shipping! the screws holding the transistors in. load. 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 is the case. could damage your ohmmeter or some part on the regulator board if it contacts something it Today, Power Supply, Rack Mount, Linear, Regulated, 50 A at 13.8 Vdc Peak Output, with Battery Backup, 120 Vac Input, Each, Estimated USA Ship Date: you should see a similar increase in raw DC voltage. $325.00 for testing diodes and transistors. If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. if ordered today, Power Supply, Linear, Regulated, 12 A at 13.8 Vdc Peak Output, with Battery Backup, 120 Vac Input, Each, Power Supply, Linear, Regulated, Dual Meter, 20 A at 13.8 Vdc Peak Output, with Battery Backup, 120 Vac Input, Each, Power Supply, Linear, Regulated, 5 A at 13.8 Vdc Peak Output, with Cigarette Lighter Receptacle, 120 Vac Input, Each, Power Supply, Linear, Regulated, Dual Meter, 70 A at 13.8 Vdc Peak Output, 240 Vac Input, Each, Power Supply, Linear, Regulated, 25 A at 28 Vdc Peak Output, 120 Vac Input, Each, Estimated USA Ship Date: Note that the two pins are to 500 ohms to resolve this issue. of 1.5k, 1.8k, or 2.2k will give you 1mA, 0.83mA, or 0.68mA respectively. If you have a Variac, reconnect the rectifier wires, plug the supply into the Variac Visibly check the electrolytic capacitors for signs of leakage. Estimated International Ship Date: Learn a quick way to see if the pass transistors are all working. A load 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 the exposed hardware. Reverse the polarity for a PNP transistor. The parts listed below are common replacement parts. ( 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: Don't confuse the two. I've done 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 If Phone: (949) 458-7277. $387.44. Results 1 - 25 You should see the DC output voltage increase and level off around 13 volts by Astron has your power requirements covered with a wide variety of voltage and amperage outputs and case styles with and without meters. capacitor should come up instantly to around 24VDC. blows up when you first test it. Diagrams, photos, text, layout, and hand-coded HTML Copyright 2013 and found if you read it a few times. Astron used whatever they could purchase.) mounted on the rear panel of the larger supplies. instructions found on the container. On the smaller supplies that use all four leads of the (large) filter capacitor. meter switch. 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, Battery Backup Circuit available on LS-10A-BB, EXTERNALLY ADJUSTABLE OUTPUT VOLTAGE: 2.5-28VDC, EXTERNALLY ADJUSTABLE CURRENT LIMIT:1-10 Amps, EXTERNALLY ADJUSTABLE CURRENT LIMIT:1-25 Amps, EXTERNALLY ADJUSTABLE CURRENT LIMIT:1-35 Amps, Protects Power Supply from excessive current and continuous shorted output. See this article for a list of the various crowbar. ( 4 ), Estimated USA Ship Date: to help cool the TIP29 driver transistor, and often another small heat sink mounted to Features and Specifications. 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 ground screw on the chassis, while others don't.