Hey there, I am looking for guidance on making a dim bulb tester for 240v applications. I understand how to make a 120v tester. For 240v, putting one 120v bulb on each leg l1 and l2 would give each bulb 240v right? How do I wire the 120v bulbs to allow 240v to the load without frying the 120v bulbs? Do I just need to find a 240v bulb to simplify things? Thanks much.
The Best way is to wire two 120 volt bulbs in series to equal on light bulb. You can wire the series light bulbs in both lines of the 220 volt supply.
Try to keep the two 120 volt light bulbs the same wattage.
Don
I’m not sure what exactly you mean… Is it a series load that you want to insert in the power line of a device under test ? In my country it’s 230VAC/50Hz, so I put one light bulb socket in series with one of the powerlines of the device under test. It’s best to connect the switch via an isolation transformer. Not directly to the mains wall plug.
You can of course integrate the isolation transformer and the switch in an enclosure, together with the on/off switch, a bypass switch for the bulb socket, and optionally a variac and voltmeter. You put the bypass switch across the connections of the light bulb socket. If you put two light bulb sockets in series, each with its individual bypass switch, you can activate either both sockets (e.g. for 120V bulbs when using 230V mains), or just 1 socket (when connecting to 120V mains), or no socket (i.e. direct connection of the device under test).
Hi, The circuit you have for the 120V lamp is exactly the same for the 240v (except, you need to replace the 120v lamp with a 240v incandescent lamp) it should all work the same. I hope this helps.
Woodb180