DC power supply

[Pierre]

Hi everyone! I’m dreaming up a new project and I thought a product like this might simplify things.
Has anyone used anything similar to this for a quick and dirty relay or dc heater supply?

https://www.jameco.com/z/IRM-20-12-MEAN ... 93299.html

https://www.jameco.com/z/RS-15-12-MEAN- ... 19051.html

They seem small enough to put in the corner of a project amp but I’m wondering if they’d introduce a bunch of noise?

[FUCHSAUDIO]

that output noise figure (200mv) seems high. I-mean, I would consider trying it, but that could be an issue. Maybe regulate a 12-V unit down to 6 volts with a 7806 to lose some noise ?

[imjonwain]

I've used a lower wattage/current version of the first encapsulated brick style in some effects pedals/preamp designs to get a split supply. It worked well but as stated^ regulation was ~100mV or so on the output and there was some noise on the output as well but it was in the high kHz/not audible. I have measurements saved somewhere on my PC I will dig up. They are however pretty sensitive and easy to kill if you do something silly or by accident on the input or output. Nothing catastrophic or exciting they just die.

The second style I can't say much besides they are reliable and I've used those type of Meanwell PS in lots of test setups and in some products in my day job. Not sure about noise but it can't hurt to try?


It's worth checking out diystompboxes for SMPS related threads as there was alot of interest in them the past few years. Some neat HV stuff to.
https://www.diystompboxes.com/smfforum/ ... ;topicseen

[Pierre]

Thanks to both of you for the reply. I’ll have to take another look at those specs. I was curious if anyone had a “go to” part that was similar and cheap and known to work in guitar amp builds. Thanks again!

[bepone]

where is a problem to add some RC filtering (1$) after this converter? to remove residual ripple?

[imjonwain]

There isn't really in this case since it's heaters. However SMPS are sensitive to capacitive loading at startup so you have an upper limit to filtering (unless you design protection in) that you need to factor in your overall C load for. The inrush to charge large C values will kill the module pretty quickly. Meanwell doesn't mention it in their datasheet but others do.

App note: This is for DC-DC but same deal.
https://www.murata.com/-/media/webrenew ... x?la=ja-jp

Traco PS datasheet for a similar model.
https://www.tracopower.com/products/tmlm.pdf

[TUBEDUDE]

They normally switch in the 50kHz and higher range, but under load the freq/duty cycle drops. Some radiated noise can still be intercepted by amp circuitry. Let us know how it fares.

[chaccmgr]

The device is industrial grade not audio grade. I would stick to proven concepts like a simple regulator circuit for switching and a crude rectification and laaarge capacitance for dc heaters.
see also http://www.valvewizard.co.uk/heater.html (bottom of the page)

[Stevem]

Noise like that can be deceiving!

It's well above what we can hear, but if it does get into the audio path somehow it can dull out the tone above a certain frequency.