madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: Axeman on August 14, 2021, 11:37:36 PM

Title: Total Recall Power supply
Post by: Axeman on August 14, 2021, 11:37:36 PM
Hey guys, I just ordered a EHX 24Vdc from Amazon for my Total Recall build.  Before adding power to the pedal, I measured the output of the power supply and I was reading 32.3Vdc.  Can I use it safely?  Any help would be appreciated.

Thanks
Title: Re: Total Recall Power supply
Post by: mauman on August 15, 2021, 12:12:36 AM
Sounds like an unregulated power supply, which has interaction between output voltage and current.  Output voltage should drop to 24V when supplying the rated current, but V will be higher at lower current (or no load) and lower at higher currents.  Regulated supplies attempt to keep V constant over a wide(r) range of output currents. Try putting a non-important load across it (lamp?) and measure the V, I'll bet it drops.
Title: Re: Total Recall Power supply
Post by: madbean on August 15, 2021, 01:11:13 AM
Quote from: Axeman on August 14, 2021, 11:37:36 PM
Hey guys, I just ordered a EHX 24Vdc from Amazon for my Total Recall build.  Before adding power to the pedal, I measured the output of the power supply and I was reading 32.3Vdc.  Can I use it safely?  Any help would be appreciated.

Thanks

All the EHX 24v PS are unregulated like that. Mine measures about the same as your reading. It's okay, the nominal voltage will drop once a load is attached.
Title: Re: Total Recall Power supply
Post by: Axeman on August 15, 2021, 01:20:17 AM
Awesome, thanks Brian
Title: Re: Total Recall Power supply
Post by: Axeman on August 15, 2021, 03:11:11 AM
It works great
Title: Re: Total Recall Power supply
Post by: Zerro on August 15, 2021, 12:55:36 PM
Such a voltage drop shows, that that power supply is very weak, so here is a danger of overheating, and burning out. With unpredictable riot going inside your Total Recal.
Title: Re: Total Recall Power supply
Post by: madbean on August 15, 2021, 03:28:12 PM
Quote from: Zerro on August 15, 2021, 12:55:36 PM
Such a voltage drop shows, that that power supply is very weak, so here is a danger of overheating, and burning out. With unpredictable riot going inside your Total Recal.

An unregulated output is sometimes less ideal but not necessarily any riskier here than one that is. The EHX PS is designed to provide 24v so long as the current draw spec is not exceeded. That output is regulated within the circuit itself.
Title: Re: Total Recall Power supply
Post by: Axeman on August 15, 2021, 03:53:39 PM
I'm getting -23.7vdc and moreover it works great