[sdiy] TapLFO question: It's 2 mints in one?

Tom Wiltshire tom at electricdruid.net
Sun Jul 19 22:09:46 CEST 2015


You can use a standard 7805/78L05 on the +15V rail. While it's dropping quite a lot of voltage, there isn't enough current drawn for it to get really warm. If you're worried about it, or you're using the +5V for anything else as well, use a 7805. The metal tab acts as a small heatsink even with nothing attached.

Alternatively, you can run the circuit on +/-12V without modifications. That way the +5V reg drops less voltage, and I'd definitely recommend a simple 78L05.
We (Rick Holt and I) did this on all of the Druid/Frequency Central euro modules, and there has never been any problem.

HTH,
Tom


On 19 Jul 2015, at 17:29, Joe Frey <joe.frey at radioles.com> wrote:

> Thanks for the quick answer. Being a cheapskate, I want to power this without spending $80 for a triple power supply. I know how to make a bipolar supply for the +-15vdc, but I am unsure whether dropping from 15v to 5v for the Taplfo is too much power to dissipate. Is it? And how would I do it?
> 
> On July 18, 2015 4:40:49 AM EDT, Tom Wiltshire <tom at electricdruid.net> wrote:
> Hi Joe,
> 
> Yes, you can add the PWM filter and offset cancellation stages from the datasheet to pin 5 and you're done. It gives a +/-5V output with the values given. If you leave off the final two op-amp stages, you get a 0-5V CV, but if you turn the Tremolo Depth down to zero, it'll finish up at the 2.5V midpoint.
> 
> If you have any problems with it, drop me an email.
> 
> Regards,
> Tom
> 
> On 18 Jul 2015, at 02:06, Joe Frey <frey at radioles.com> wrote:
> 
>  Hello, for those not in the US the subject is a poor attempt to be funny based on an ancient tv ad.
>  Anyway, I have a Tapflo chip and a nice Taylor Livingston made tap tempo tremolo board. I want to add a daughter board that adds a 0-5V CV output for use with my Moog stuff. I know how to use EagleCad. Can I just add the circuit from data
>  sheet
> for a modular synth lfo onto pin5 of the lfo, so I can have the tap tempo tremolo and a CV out in one box? Thanks.
> 
>  
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