Good Bench Top Power Supply?

[Zerotolerance]

I am looking to buy a cheap, but good benchtop variable power supply to do small electronic repair such as tvs, stereos, and common househole appliances. Any suggestions are greatly appreciated.

 

[squishy36]

Well, your first job is to state what price you want to keep it under and what voltage/current levels you want. Otherwise, you're just asking for a piece of rope -- and any piece will suffice. Do you want digital readouts or will analog meters suffice? What regulation levels do you want? Do you want constant voltage or both constant voltage/constant current? How fine of a control do you want over voltage and current? Do you want remote sensing? Do you want digital control via a computer? Do you mind if the output doesn't go below a certain voltage (e.g., 1 volt)? You see there's lots of stuff to think about.

 

[saturation]

See this for ideas:

https://www.electro-tech-online.com/threads/new-bench-power-supply.118204/#post1003766

 

[KeepItSimpleStupid]

Variable AC? Isolation? DC, Range?

Help!

 

[Zerotolerance]

All Good questions. I am a complete amatuer when it comes to diagnosing electronic components but feel I have a good grasp of A/C circuits. I am just looking for something that will suffice to do small repairs such as radios/receivers, tvs, alarm clocks, and other small household appliances.

 

[carbonzit]

Let me take a stab at a guess for what the O.P. needs:

• 0-30 volts, fairly well regulated (5%)
• 5 amps, no current regulation (but short-circuit protection)
• Analog meters (my preference)
• Dual supply (never know when you'll need 2 V+s)
• No remote sensing, external interface, other fancy-schmancy stuff.

Sound close, O.P.?

 

[Zerotolerance]

Yes, this is in fact was what I was looking at, but was told I will probably need more volts for household appliances?

 

[squishy36]

He's a newbie and has posted his question on multiple forums. I just got done reading some of his responses elsewhere and it's clear he doesn't have the knowledge yet to specify much in detail -- he wants to start troubleshooting and fixing things and someone must have told him that he needs a DC power supply. Others on that other forum have told him he needs to learn more basic stuff first and build a few projects. Then he'll have better knowledge about what he wants.

 

[Zerotolerance]

Yes, I am a complete amatuer NOOB when it comes to this stuff, and yes I have posted on other boards to get more unbias responses. I am trying to soak up as much knowledge as I can on this subject (repairing electronics).

Do I actually need one of these? Only reason I was thinking I needed one was to power a logic pulser or the superprobe I was planning on building. And maybe even helping power CB's that have bad transformers to see if any of the components have been damaged by the transformer blow out

 

[carbonzit]

Yes, this is in fact was what I was looking at, but was told I will probably need more volts for household appliances?

Well, the next step up is 50 volts. Like this benchtop supply from Jameco (for about $130). Single supply, 0-50V @ 3A.

For most work, the most you're going to need is probably 12 volts.

If you're going to work on appliances (i.e., largely non-electronic devices), then another way to go is to get a Variac (a variable-voltage transformer) so you can slowly ramp up the voltage to check for faults. However, these ain't cheap.

You still haven't told us what your budget is.

Another way to go, especially if you're a (self-admitted) n00b and want to learn stuff about electronics (and do it cheap!) is to get an old ATX computer power supply and convert it to a bench supply. I've done this, and it's a great, cheap way to get 12, 5 and 3.3 volts on your workbench. If you're interested, I can give you some links on how to do this, or you can find them yourself out there on the web. This will work for 99% of what it sounds like you'll be doing in your quest to learn electronics.

 

[Zerotolerance]

$160 Max

 

[carbonzit]

Then the supply I linked to would fit your bill nicely. All the dual-output supplies I found (at Jameco, anyhow, which tends to be cheaper) were over $200.

 

[KeepItSimpleStupid]

Is a CB a "Children's Band" Radio? i.e Citizens' Band?

Car radios require a power supply and 3A may or may not be sufficient, but it's a good start. Most other repairs do not.

The modern TV, almost always requires an Isolation transformer.

Amplifiers and vintage radios almost always requires a variable AC power supply.

Building your own stuff usually requires multiple supplies.

 

[Zerotolerance]

sorry... pcb

 

[carbonzit]

So, what are you going to do?

 

[Zerotolerance]

What do you mean?

 

[carbonzit]

What kind of power supply do you plan to buy (or build)?

 

[mvs sarma]

I fear, that a total newbie might have problems with variable power supply. in case he doesn't set the voltage and current limits, he would be further spoiling the already faulty equipment, that he proposes to service.

Perhaps it might be better for Zerotolerance to take a short course on electronic servicing before embarking on using bench power supplies on faulty equipments.

 

[Zerotolerance]

I am doing this as a hobby, If I break stuff further than what it is already.... Oh well, it's my money, my loss! As long as I have a schematic, I should be fine with supplying voltage and current to the boards. I'm not going to go add 120v to a 24v circuit haha, and just start guessing at things. I do have common sense.

I don't have time to go take a "course" I've taken enough college courses in my life lol

I am not a newbie when it comes to electricity, just when it comes to "electronics". I have experience with commercial and residential power distribution and commercial kitchen appliance repair. As long as I have a service manual and/or schematic I will be fine.

 

[mvs sarma]

that speaks, great of you. so what Carbonzit suggested appears a nice power supply to fit to your budget. I had enough of this servicing in my life
I enjoy and wanted to caution as you indicated that you are a noob. You took it in right perspective. Thanks.