Completed Project What is the max current this relay can handle? Using US 240V for German 240V transformer?

Thread Starter

Rahulk70

Joined Dec 16, 2016
536
Hi everyone,

I'm designing an automotive battery charger. I plan to have two modes in it i.e, a Regular 1A mode and an 8A Fast mode. I've managed to find in my collection an old slightly rusty German made Bosch 220-250VAC-14V/9V 10A 132KVA 50/60Hz (salvaged from an old charger long ago) transformer. I've also managed to get an old selenium rectifier too from a friend.

I plan to to reduce current for 1A mode with a power resistor/bulb technique and Fast mode runs ar full power. I plan to add a switch to realize this through a relay. Unfortunately this is where I'm slightly confused. I've a DC 12V 6A relay which will not do the job well and a 120VAC 1/3HP 10A relay.

My questions are as follows:
1.For obvious reasons even though the transformer can handle upto 10A. So the DC relay is no good I guess. But the AC relay has three terminals. each for COM,NC & NO(likely 3 phase). Does the specs mean each line on relay can handle 10A or its in total 10A?

2. Also since this is a 220-250V, 50/60Hz German transformer,I'm planning to connect it to my 110V to 220V step up voltage regulator in my garage. Just a curious dumb question can I use it on my air conditioner 240V(actually 236V when I measured) outlet? Which in this case I'll not be able to use my 120VAC relay if this method works:rolleyes:

Thanks.
 
Last edited:

AlbertHall

Joined Jun 4, 2014
12,345
How you going to operate the relay - with a manual switch? In which case you don't need the relay, the switch can do the job directly.
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
536
How you going to operate the relay - with a manual switch? In which case you don't need the relay, the switch can do the job directly.
The switch I intend use is the regular ones that we normally have in devices like 3-5A ones. The only 10A I have on hand are the Leviton wall outlet type.
I do have a universal car ignition switch but don't know it's specs. But still I need to switch between slow and fast charge rates.
 
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