Electronics for Dogs V · 17 October 05
To make an electric car you’ll use a few relays, a fair bit of wiring, and a bunch of batteries. In this circuit we are only showing the high voltage section of the EV. The circuits that turn on R1 and manage some of the other functions are low voltage, or 12vdc.
You really don’t want to mix the high voltage and low voltage circuits. It’s not good for the equipment and it certainly isn’t good for the operator. When drawing an EV circuit use obvious colors and/or line styles for the high voltage lines, and different colors/styles for the 12vdc circuits (even the ground wires are different). This makes it easier to keep the circuits straight.
Additional items that you might add to your high voltage circuit:
- circuit breaker – high voltage DC, not AC
- safety cutoff – a “big red switch” in case of emergency
- DC-DC converter – the turns the high voltage into low voltage DC to charge the normal battery (it provides isolation)
- ammeter – hooked to Shunt (S1) to shows current draw
- voltmeter – to show battery voltage level
- amp hour meter – keeps track of how much power you use (or replace when charging)
- fuzzy dice…
Now on to Electronics for Dogs VI