Why are good bench PSUs so bloody expensive?

Frustration!    Being a hobbyist can be expensive!   Or you end up frustrated with cheap and often crap equipment.

In my day job I have access to lots of very nice and very costly test equipment.   I use scopes that cost more than my car, spectrum analysers that cost more than my last 3 cars combined and nice bench PSUs that cost more than my last holiday.

At home I’m using a PSU that I made for myself based on a Maplin design.   I made it some time around 1990/1 and it has a series of fixed outputs all based on 78xx and 79xx regs.   Hardy rocket science but I was still in secondary school.   PCB was made using marker pens and ferric chloride solution.

It works but it has no adjustable current limit, each output is only capable of 1A (some are 500mA but I can’t remember which any more!) and 15V is the highest output.   I really want something 0-30v, up to 4 or 5 amps, adjustable limits and ideally 2 outputs.

If I go with a nice TTI dual output PSU similar to the ones I use at work I’m looking at best part of £480!   Ouch, too much!   However we’ve only had 1 fail in 12 years.

OK, lets turn to ebay.   Lots of PSUs on there but they have some issues.   This one is cheap-ish but suffers from the age old issue dogged by cheap PSUs, it only has 1 power switch.   So you have to disconnect the EUT, adjust the volts and current then reconnect.   Yuk!   I’ve used them, horrible!   Not really a step up from my home made one.

Now it looks like Tenma might come to my rescue!   I have a tenma multimeter and it works pretty well.   So for just over £100 this might be the one.   Maybe I’ll buy myself one.