UMR with Casio SK-8

[John]

B. writes:

I wanted to drop you a line and ask you if the current version of the UMR is cool for the Casio SK8? I see that you listed the SK1, 5 and 10. The 8 looks very similar to the SK5, but I thought I should ask before I bought one.

The UMR will work fine with the SK-8. The install is just like the SK-5 install, but there is one extra consideration:

The SK-8 positive voltage rail is not 5V, but rather 8V or so, depending on the power source used. The UMR can operate from 6.5V at absolute maximum. So you'll have to regulate the SK-8 power rail down to 5V or so. This is easy to do. You can do one of the following:


Use a 7805 regulator to supply power to the UMR.
Use a zener diode as a voltage regulator.


Check out the "Regulator" section of this page:

http://www.kpsec.freeuk.com/powersup.htm#regulator

Hope this helps--please let me know if I can provide more info.

[painfulleg]

John,

Thanks for answering my question about the sk8. So in this case the installation of the zener diode would be similar to how one was implemented into the Speak retrofit kit?

Glad to see the forums here.

wb

[John]

Thanks for answering my question about the sk8. So in this case the installation of the zener diode would be similar to how one was implemented into the Speak retrofit kit?


Well, somewhat, yes. The MIDISpeak does use Zener diodes to limit the voltage of the Speak's "PMOS" logic to 5V.

...if you use a Zener diode with the UMR/SK-8, make sure to include the "resistor to limit current" as shown in the link above. Something in the 100ohm-1kohm range should work.

[painfulleg]

Well, it turned out that I did have a 7805 regulator. Super-easy, works great.

Thanks!

wb

[heat00hunter]

*Edit: ok no probleme for the power