1) when using a small NPN transistor (or PNP for that matter) as a switch, does it matter if the load is on the collector or the emitter? (If it makes any difference, the load is a 12V, 400 ohm relay coil.)
2) On the above coil would a diode be necessary to stop reverse current into the transistor from the coil? If so, would it be in series with the coil, or across the coil in parallel? It seems like I've seen them both ways.
2) On the above coil would a diode be necessary to stop reverse current into the transistor from the coil? If so, would it be in series with the coil, or across the coil in parallel? It seems like I've seen them both ways.