If you're building or modifying guitar pedals, you may find that the standard 9 Volt power supply isn't getting it done for you. Perhaps you'd like to have a dual-supply op-amp circuit or maybe you have a transistor circuit that's hungry for more voltage. Either way, this little doo-dad can help.
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Our voltage doubler takes an input of 3.0 Volts to 10.0 Volts (don't exceed 10.0 Volts or you may let the magic smoke out) and provides the same voltage as well as its negative equivalent. So, for example, if you put 9 Volts in you'll get +9 Volts, ground, and -9 Volts out. If you don't need a dual-supply, you can ignore the ground output and use the negative output as ground in your circuit, giving +18 Volts for this example. Handy as a shirt-pocket!
If you'd like to make your own or incorporate it into your own circuit board, the schematic is available.
The circuit board is 1.4 by 0.85 inches. The solder terminals are sized to accomodate 18 gauge or smaller wire. The TC7660 has a built-in oscillator. Our circuit includes filtering on both the input and output, but for sensitive applications you may still wish to make sure that the frequency of oscillation is outside the frequency response of your circuit. Different versions of the TC7660 are available which oscillate at different frequencies. The TC7660H oscillates at about 120kHz. It has a typical output impedance of 55Ω 20mA, a typical power efficiency of 85% at 10mA, and a typical voltage efficiency of 99.7% (open circuit).
Aside from the TC7660, only two resistors and five capacitors are required for this circuit. You should be able to get everything from an electronics distributor like Digi-Key or Mouser. Here's a typical parts list:
|1||Charge pump IC||Microchip Technology||TC7660HEPA|
|2||10Ω 1/4W 5% resistor||Yageo||CFR-25JB-52-10R|
|5||100µF 16V 20% capacitor||Nichicon||UVR1C101MDD|
I hope that this circuit is helpful to you! If you have any questions or if there's anything else we can do, please don't hesitate to drop us a line. If this is the kind of thing you're into, you may enjoy our other work.Parks Digital LLC