What should be the power rating of the StepDown Transformer?

AI Thread Summary
To safely use a US 110v antique chemical photobooth in a 220v country, a step-down transformer is necessary, ideally rated with a power demand plus a safety margin of 2:1. The term "VAL" in the circuit diagram refers to voltage value, with no current restrictions specified. Users should verify the output voltage with a multimeter before use, especially if the device is heavy, indicating it may handle higher loads. A clamp-on amp meter can measure current without cutting cables, and the circuit breaker or fuse rating of the current setup can provide additional safety insights. Understanding the power demand of the antique device is crucial for selecting the appropriate transformer.
Yam
Messages
32
Reaction score
1
Dear Forum Members,

I imported an electrical equipment from the US which uses 110v, my country used 220v and as such i need to pirchase a step down transformer.

The equipment is a piece of antique and doesn't come with much instructions. I could only get a circuit diagram and i am puzzled by what is VAL. Could anyone help me out?
 

Attachments

  • Screenshot_2016-02-20-14-22-24.png
    Screenshot_2016-02-20-14-22-24.png
    45.5 KB · Views: 411
Engineering news on Phys.org
Yam said:
The equipment is a piece of antique and doesn't come with much instructions. I could only get a circuit diagram and i am puzzled by what is VAL. Could anyone help me out?

As i saw your circuit its a one step -down transformer such that if you input 240 volts it can give an output of 115 volts - naturally the number of turns in the primary and secondary have been adjusted to give this output . i could only that VAL. refers to the value of the voltage -there is no restriction on current given - but before using it one should check by a multimeter the real output voltage with a main line input-just to be on safe side- if the equipment is very heavy say 10 kg or so then it may be rugged one and can withstand higher load-that is my guess!
 
Any answer to your question must begin with the power demand of your as antique device, plus a safety margin such as 2:1.

If you don't know how much power your antique device uses, your question can't be answered.
 
anorlunda said:
Any answer to your question must begin with the power demand of your as antique device, plus a safety margin such as 2:1.

If you don't know how much power your antique device uses, your question can't be answered.

I can't seem to find any information of the power demand of this equipment, its actually a large antique chemical photobooth.

Ill do my best to search for the power demand
 
drvrm said:
As i saw your circuit its a one step -down transformer such that if you input 240 volts it can give an output of 115 volts - naturally the number of turns in the primary and secondary have been adjusted to give this output . i could only that VAL. refers to the value of the voltage -there is no restriction on current given - but before using it one should check by a multimeter the real output voltage with a main line input-just to be on safe side- if the equipment is very heavy say 10 kg or so then it may be rugged one and can withstand higher load-that is my guess!

After getting a multimeter, is there anyway i can measure the current without cutting the electrical cables?

I have the circuit diagram of the entire system, would it help if i uploaded it? not too sure if i am allowed to do so or not too.
 
Yam said:
After getting a multimeter, is there anyway i can measure the current without cutting the electrical cables?

I have the circuit diagram of the entire system, would it help if i uploaded it? not too sure if i am allowed to do so or not too.

Yes, a clamp on type amp meter can measure current without breaking the circuit. Just make sure that it is clamped on only one of the two conductors to the wall plug.

A circuit diagram will probably not help.

If it is plugged in and working now, what is the fuse/circuit breaker rating of the circuit it is plugged in to?
 
Last edited:
  • Like
Likes drvrm
Very basic question. Consider a 3-terminal device with terminals say A,B,C. Kirchhoff Current Law (KCL) and Kirchhoff Voltage Law (KVL) establish two relationships between the 3 currents entering the terminals and the 3 terminal's voltage pairs respectively. So we have 2 equations in 6 unknowns. To proceed further we need two more (independent) equations in order to solve the circuit the 3-terminal device is connected to (basically one treats such a device as an unbalanced two-port...
suppose you have two capacitors with a 0.1 Farad value and 12 VDC rating. label these as A and B. label the terminals of each as 1 and 2. you also have a voltmeter with a 40 volt linear range for DC. you also have a 9 volt DC power supply fed by mains. you charge each capacitor to 9 volts with terminal 1 being - (negative) and terminal 2 being + (positive). you connect the voltmeter to terminal A2 and to terminal B1. does it read any voltage? can - of one capacitor discharge + of the...
Thread 'Weird near-field phenomenon I get in my EM simulation'
I recently made a basic simulation of wire antennas and I am not sure if the near field in my simulation is modeled correctly. One of the things that worry me is the fact that sometimes I see in my simulation "movements" in the near field that seems to be faster than the speed of wave propagation I defined (the speed of light in the simulation). Specifically I see "nodes" of low amplitude in the E field that are quickly "emitted" from the antenna and then slow down as they approach the far...
Back
Top