Electronics Lab Philippines

Electronic Bongos

Offline Super zHero

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Re: Electronic Bongos
« Reply #80 on: October 07, 2020, 12:43:02 PM »
With the values of R1, R2 & C2 in the schematics and PCB layout, the output freq is about 315Hz.  The ripple of the charge pump output voltage came to around 232mVpp as shown here:


Offline Super zHero

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Re: Electronic Bongos
« Reply #81 on: October 07, 2020, 12:58:09 PM »
On my solderless prototype, the value of R2 was 20K and C2 was 4.7nF (472), so my freq was about 6.8kHz.  I don't have 4.7nF in 1206 SMD so I just used 10nF or 0.01uF on this version.  The freq is around 3kHz:



The ripple is down to less than 74mVpp as shown above with a 1K load resistor.