Ac to dc Conversion

Most recent answer: 11/08/2011

Q:
lets say i want to convert high voltage ac power over to dc to charge batteries large enough to power a standard home. what kind of circuitry am i looking to put together to safely convert this energy?
- cody (age 20)
marietta ok usa
A:
By "high voltage" I assume you mean one of the standard home line voltage, say 115 V ac or ~200 V ac. The standard thing to do is to run it through a step-down transformer to get lower voltages. The transformer output (secondary) is then connected to a four-diode full-wave rectifier bridge. The output of that bridge is dc with a big ripple at twice the line frequency.

Basically this is what the chargers for automobile batteries do. They also usually have some additional active circuitry allowing some control over battery charging rate. Since these are mass-produced I bet that they're the most convenient cost-effective way of charging big batteries from line power.

Your home, however, probably has appliances that are designed for ac power. In that case, you'd also need an inverter to reconvert the battery voltage to ac and then a step-up transformer to get it in the right voltage range. This sort of circuit also is widely available commercially (along with charging circuits), since that's what people use for emergency backup circuits.

Mike W.

(published on 11/08/2011)