5v pulse to 12v?

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Dear sirs

I posted about this in the main DIY forum, but so far no bites... I should have known better and just posted it here right away.

I have a TR-505 that I just got from a thrift store that I want to circuit bend and also send clock info to my CMOS synth stuff so they can all play together like happy friends.

I found a clock signal on the 505's board, but when sent to my analog sequencer, it will not advance.

My non scientific guess is that the 505 is putting out only a 5v pulse and my sequencer is running on 12V.

What would be a good way to amplify the 5v pulse up to 12V to play nice with my other stuff?

CMOS based, of course...

[tjookum]

For a fast and ugly test just run the cmos synth also at 5v, might even be interesting.

[blue hell]

[DGTom]

I know op-amps are kinda taboo / off limits / not purist around here, but, this is just the kind of thing you'd use a comparator set-up like one of the ones I posted awhile back.

Plugging stuff randomly (via a diode / resistor) into CMOS can be cool but sometimes you want solid + predictable behaviour... if only so that you can get crazier / wonkier further down the chain.

I bet that clock inside the 505 is really tiny as well, not just the voltage, but, the pulse width. By squareing it up & slamming it into the 12V rail with a 358 you could then use it to toggle a 4013 flip flop & get something out of it that will work with anything

[electri-fire]

Make sure the Ground of the TR505 and CMOS circuits are connected. If I'm correct, a CMOS Schmitt triggering input should be able to go Hi at about 1/3 of the positive voltage, so in this case from 4 Volts.

EDIT: Oops...Nope, it goes LOW at about 1/3 of the voltage, it goes Hi at about 2/3 of the voltage, so at +- 8V , running a 12V CMOS.


A lot of CMOS ICs have schmitt trigger inputs even when this is not specifically mentioned.
Exact minimum trigger values are in the datasheets.

[electri-fire]

Indeed the TR505 circuit runs on 5V. Can you post a pic of where you tapped of the TR505 clock?

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Thanks for the advice guys... some of this stuff I will need to look up/look into more because I wasn't familiar with everything mentioned.

I did make sure the grounds were connected from the two devices though.

The analog sequencer is based around a 4017, so I will check the datasheet to see what the minimum voltage is to trigger it.

[electri-fire]

Oops, error report on the Schmitt Trigger thresholds. Corrected above...

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[Psyingo]

you could use a couple inverters to make an amp. run the signal into the inverter with a feedback resistor from out to in as well.. experiment with resistor values to get it up to 12v try maybe 100k to start? then run it into another inverter to bring it from being inverted.

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