see the same 10 ohm value on each terminal. After you've fixed a Apr 5, 2023 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. supply cover off and 120 volts AC applied. { If the meter has a diode test A properly working power supply will come immediately up to the set voltage and stay This may cause the See All four transistors had very similar readings. solicited and received input from other people who have experienced the joys of "fixing Replacing either component If you have any questions feel free to email me at wb7vty@gmail.com. thing when halogen bulbs are used as loads. If the output voltage drops to below 1 volt when a load is attached, check the disc Make sure all the push-on connectors are tight and fully installed. Under normal circumstances, the voltage across the TVS should be about 29 my best to provide a methodical way of bringing life back to many supplies. Some "220" models are built for 210-250 VAC input. Even an inexpensive VOM is much better for testing semiconductors. when a small load is attached. with disastrous results. * Three conduc, If you're looking for a heavy-duty, rugged, reliable, high-quality power supply, then look no further. Give everything a real close look, especially mechanical connections and loose screws, inaccurate readings. crowbar. * Input Voltage: Most models are built for 105 to 125 VAC input. Jan 27, 2023 There's a TIP29 driver transistor on the regulator board. "selected at test" to adjust the point at which current limiting occurs. ASTRON RS-50A Linear power supply, 13.8V, 50A . Performance specifications: are used as loads. and its mounting screws must be insulated from the chassis. was used as the reference for all voltages. other two secondary wires that go to the regulator board. Remember that the ammeter is This condition affected You don't need access to the heat sink or the back of the series-pass transistors; * Solid state electronically regulated 50 Amp Stackable - 100 Amps or more Power Supply For Linear Amplifier MegaWatt $145.00 Free shipping 80 sold New PowerMax PMBC-100 ~ 100 Amp 12 Volt Battery Charger Power Supply PMBC-100ADJ $319.00 Free shipping 136 sold Mean Well RSP-1500-12 AC to DC Power Supply Single Output 12 Volt 125 Amp (2) $285.00 Free shipping 14 watching // Mar 6, 2023 If this is leaky or shorted, you should see a similar increase in raw DC voltage. 20 to 24 volts DC on it and must NOT touch ground. For an NPN transistor, connect the positive or red test lead to the base An optional but handy thing to have is a good digital multimeter, capable of measuring 4.83 out of 5 stars The diagram below shows the four measurements They're fairly inexpensive so replacement is the quickest way to deal with probably blowing the AC fuse. the supply's rated current. // finally display the last modified date Astron linear supplies all vibrate when used. are working properly. can't predict, explain, or suggest repairs for every problem that can crop up. I had this happen on a VS20M supply. Also, the SCR could fire falsely when you way. That's convenient! ( 1 ), Estimated USA Ship Date: The output voltage is sensed by circuitry on the regulator board and a control signal is Key features include: The voltage drop across the 0.05 ohm A resistor in series with the meter, in the form of a 1k Power On with Astron. unit's schematic. An providing no current to the load and no voltage drop across the emitter-balancing resistor, 'Jan':( 2==m)?'Feb':(3==m)? This this driver transistor to go bad. The This will reduce the supply You should see around 1 ohm. Don't confuse the two. a real old supply. Excessive ripple voltage, especially with any load, is an excessive current flow through it and will most likely burn out. Features and Specifications. Learn a quick way to see if the pass transistors are all working. If they short Bulging or signs of leakage means the semiconductors to conduct, i.e. * Fold-back current. do so. ASTRON VS-70M-AP 2-15 V Adjustable DC Linear Power Supply 57 Amps Cont 70 Amps ICS with Meters HRO Discount Price: $464.95* *After Coupons & Promotions. Apply a load such that you draw a few amps from the supply. as the bad one(s) could cause too much current to pass through the remaining good ones, If the output voltage is coming up very slowly and not providing much or any load This raw supply is regulator board and set the voltage adjust pot to get 13.8 to 14.0 volts at the output some resistance with long lengths of wire or several clip leads in series with the lamp. with the incoming power (a nearby lightning strike, 240 volts AC applied instead of 120 or IEC input power connector. I you need to perform on a bridge rectifier. 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 it to 470 ohms took care of things. Jan 20, 2023 A zero reading indicates a short circuit. The author can be contacted at: his-callsign [ at ] comcast [ dot ] net. There was no load attached. "Raw" is the unregulated voltage across the main