I tried to build a kind of R/C catamaran working with computer fans using an R/C car circuit (27 MHz). The original circuit uses 6V batteries but the fans uses 12V. To make the fans faster, I've given first 18V and once seen that nothing goes wrong, I've added another 9V to make the tension up to 27V. Of course a component couldn't resist and blew off. Here is the picture of the circuit :

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As a result, I decided to rebuild a similar circuit with adequate component that would support up to 27V at least. So I'm asking here what are the components that I would need to build this circuit and if possible, I'd like to have a scheme of the circuit since I don't know much about this.


migrated from physics.stackexchange.com Jul 4 '13 at 23:29

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  • 1
    \$\begingroup\$ I don't trust the green components. Delete them. \$\endgroup\$ – Trimok Jul 4 '13 at 15:29
  • \$\begingroup\$ @Trimok What are them ? \$\endgroup\$ – moray95 Jul 4 '13 at 15:48
  • \$\begingroup\$ I guess so but I discovered this site just after posting the question... \$\endgroup\$ – moray95 Jul 4 '13 at 19:18
  • \$\begingroup\$ @moray95 This is pretty off-topic for us, but may be on topic on electronics (no guarantee, I'm not an active member there). You can flag your question or ping Qmechanic to request the question be migrated to that site. \$\endgroup\$ – Chris White Jul 4 '13 at 19:49
  • \$\begingroup\$ Thanks but I've already solved my problem :) \$\endgroup\$ – moray95 Jul 4 '13 at 20:41

The part that blew up is a capacitor, most likely across the input power and ground wires. This helps smooth out the power going into the circuit, but it has electrical limitations. If you exceed the voltage printed on the side of the capacitor, it blows up. Replace it with a same capacity and higher voltage device.

Assuming your R/C circuit still works, I'd suggest using a circuit to bridge the gap between your R/C circuit and your fans. If the R/C circuit output is linear, you can use an opamp and NPN power transistor wired as a 3X voltage amplifier. Thus a 6V output from the control will give you 27V at the output of the amplifier. This will also give you much more current to your fans than your R/C board can provide, saving you from replacing the dinky little transistors there.

  • \$\begingroup\$ Not if it was what you said but I handled the circuit using 2 relays one for each fans... \$\endgroup\$ – moray95 Jul 4 '13 at 19:17

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