thank you in advance - I am looking for an inexpensive power supply - ac dc that i can use on workbench to energize components - too many to choose from in G-search so looking for some help -

 

What voltage and current do you require?

 

120v variable amps -
but also 12v DC

 

120v variable amps -
but also 12v DC

You need to be more specific.

120V DC output??
Maximum current required?
Only 12VDC fixed? No variable output?

 

looking for 120V input that can output 120v AC as well as step down for 12vDC output
Current max - ? devices on bench are low drawing consumer electronics and or parts -
- i could use a power cord with pigtails and 12v deep cycle batteries but or 9v batteries but looking for something more versatile.
Power Supply - 80W DC Switching Mode - type is good but only outputs DC - ebay sells some in $50 range

 

Your 120VAC out requirement seems kind of odd. For that, I would get an isolation transformer. If you want variable AC, get a variac.

You need to think through what you are going to use it for. max voltage, max current. multiple outputs.

For low voltage DC, I'd look at getting a bench supply. Here's what I have - dual channel 0-30V unit that can supply up to 5A each. each channel has a dial for current limiting and I use it all the time. I'll set the limit to about 50% over my expected draw. If there's a short or current draw above the setting, the supply cuts off. It has voltage and current displays per channel. It's great for accidental shorts and such. I've lost count of how many times it's saved my project or power supply. It's a chinese knockout but it's been very reliable. I think I paid around $120 10 years ago. Similar units go for around $200

I could probably live without dual channel, 5A (3A would be OK) and 30V (0-18V would be fine). You can get a decent single channel 0-18V 3A supply for well less than $100.

The one thing I wished it had was better resolution on the current display. Mine only support 2 decimal places (i.e 10 mA accuracy). I'd like to at least have 1 mA or even 100 uA resolution.

 

thanks - i found a youtube fella with lots of equipemnt setup information - and will study this too - thanks again