Say if I have a 120V primary 42VCT 100VA transformer - can I use it with 240V input to get a 84VCT output and 1/2 max (at the limit) current output to maintain same max 100VA rating?
Any problems or dangers of doing so?
thanks
her shann
Any problems or dangers of doing so?
thanks
her shann
You cannot do this. The transformer will saturate and the primary currents will be very large. This will damage the transformer or blow a fuse if you have one.
Hi Hershann
Stop !!, you will need two transformers rated at 120v then wire the
primaries of two identical transformers in series to get Sec + Sec Voltage
if you don't have two transformers the only other option is to use a step down transformer to reduce 240v to 120v then feed 120v to your existing
tranformer.
If the step down is the way to go you could use a 240v transformer with CT 63v 0 63v secondaries, ( sadly 60v 0 60v transformers are rare) wire the secondaries in series to make 126v Ensure any such step down or other transforner is rated at sufficient current for your project
Hope this helps / Chris
Stop !!, you will need two transformers rated at 120v then wire the
primaries of two identical transformers in series to get Sec + Sec Voltage
if you don't have two transformers the only other option is to use a step down transformer to reduce 240v to 120v then feed 120v to your existing
tranformer.
If the step down is the way to go you could use a 240v transformer with CT 63v 0 63v secondaries, ( sadly 60v 0 60v transformers are rare) wire the secondaries in series to make 126v Ensure any such step down or other transforner is rated at sufficient current for your project
Hope this helps / Chris
Thanks all for the reply, just wondering about it. Gotta read about saturation then - it not as simple as the ratio of primary coil over the secondary coil then.
her shann
her shann
Core saturation
The majority of core losses in a power transformer are caused by the magnetizing current, a highly non-linear current that is dependent only on the voltage, not the load current. As the transformer core nears saturation, the magnetizing current starts to dramatically go up. Good transformers are designed to have low magnetizing currents (although doubling the primary voltage would still be way out of bounds), while cheap ones (i.e. Stancor and Triad filament transformers) have pretty high magnetizing currents. You can tell because they get hot even with no load on them.
You can run a 240V transformer on 120V with no problem, except that there is "extra" windings, so it is not quite as economical to build.
- John Atwood
The majority of core losses in a power transformer are caused by the magnetizing current, a highly non-linear current that is dependent only on the voltage, not the load current. As the transformer core nears saturation, the magnetizing current starts to dramatically go up. Good transformers are designed to have low magnetizing currents (although doubling the primary voltage would still be way out of bounds), while cheap ones (i.e. Stancor and Triad filament transformers) have pretty high magnetizing currents. You can tell because they get hot even with no load on them.
You can run a 240V transformer on 120V with no problem, except that there is "extra" windings, so it is not quite as economical to build.
- John Atwood
It is pretty straightforward to convert 240v to 120v with the help of a half bridge converter. (Or even more straightforward to get 120v from hot to neutral as 240v is from hot to hot.)
You can also turn up the frequency (while keeping voltage about the same) with a H bridge to avoid core saturation, but insulation might be a problem.
You can also turn up the frequency (while keeping voltage about the same) with a H bridge to avoid core saturation, but insulation might be a problem.
star882 said:
That may well be the case in the USA but alot of the rest of the world that has grown up on 220-240V AC mains supply runs 230V on the hot and the other conductor is at ground potential.
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