Electric Mistress V2 - ideal DC voltage

Started by yeeshkul, November 01, 2017, 01:16:20 PM

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yeeshkul

Guys i am building my own clone of the old V2 18V fed Electric Mistress. I am about to power it via a 15V voltage stabilizer 7815.
The original unit was fed from 12-13.5V.
Is there any reason not to feed it from 15V? It looks like the clock pulse amplitude follows the DC voltage.

My original Mistress is very noisy, so i decided to design my own PCB, with two separate grounds and DC paths, one for the clock circuit and other for the audio circuit, with some filtering in between the DCs so the clock noise doesn't appear in the audio DC path.

Scruffie

Can't see why not, I would think the lower voltage originally used was just to get some more life out of the batteries.

maartendh

If there are any CD40XX chips in it, 15v would be the absolute max voltage, IRC. Staying a bit below that is good practice.



yeeshkul

Quote from: maartendh on November 01, 2017, 01:34:49 PM
If there are any CD40XX chips in it, 15v would be the absolute max voltage, IRC. Staying a bit below that is good practice.

There is 4013 in it. The datasheet shows +18V maximum. Operating values 3-15V.

maartendh

15 v is fine then, provided you looked at a datasheet of the same brand as the 4013 you are going to use - max values may vary somewhat between different manufacturers.

Maybe the schematic dates from a time when max specs were a little bit lower...

M