Can I add a step-down transformer to use a 220v DC power supply on 120v?

[Electronics123]

I have a DC power supply made for a 220v country but I have 120v where I live. Can I just wire-in a step-down transformer between the mains and its internal power supply or is there more to it?

 

[KlausST]

Hi,

the question is unclear. Draw a sketch.

But generally transformers are not suitable for DC.

Klaus

 

[betwixt]

Generally, as long as its done on the mains AC side and the step-down transformer is sufficiently rated, you should be OK. Things to be careful of are the power rating and AC mains frequency. Most 120V countries use 60Hz mains and most 220V countries use 50Hz, there are small differences in the transformer design to cater for the frequency difference. If your power supply has a power rating on it (Watts or VA), use a transformer with at least that rating and preferably add at least an extra 10% to allow for inefficiency in the transformer itself. Using a step-down transformer with even higher ratings is not a problem.

Brian.

 

[D.A.(Tony)Stewart]

> Can I use step-down transformer to use a 220v (AC to )DC power supply on 120 (Vac)?​

No. You need to step-up the voltage.
AC to DC supplies rectify and charge up low impedance capacitors quickly to store energy and this may exceed the current rating and saturate the transformer on start-up and thus blow a fuse or burnout unless rated for the surge current of the supply.

 

[Easy peasy]

If you have a 1:1 isolation transformer you can connect the output of this in series with the power to the input to get 2 x the input voltage

so about 220Vac - which appears to be what you are seeking.

 

[khadsid]

I have a DC power supply made for a 220v country but I have 120v where I live. Can I just wire-in a step-down transformer between the mains and its internal power supply or is there more to it?

Employing a step-down transformer to adjust a device designed for 220V to function on a 120V control source is indeed a doable solution. However, there are a number of variables you wish to consider:


1. Control Rating:
Guarantee that the step-down transformer can handle the control necessities of your DC control supply. Calculate the control utilization of your DC control supply (in watts) by duplicating its input voltage rating by its most extreme input current. Select a step-down transformer with a control rating higher than this calculated esteem to guarantee it can handle the stack.

2.Voltage Change:
Make beyond any doubt the step-down transformer diminishes the voltage from 120V to an fitting level for your DC control supply. For illustration, on the off chance that your DC control supply requires 220V, you'd require a step-down transformer that changes over 120V to 220V. Transformers are labeled with their input and yield voltages, so guarantee you select one that matches your needs.

3. Compatibility:
Check the input voltage extend of your DC control supply. A few control supplies have a wide input voltage run (e.g., 100-240V), in which case a transformer might not be necessary.

4. Physical Space:
Consider the measure and space prerequisites of the step-down transformer. Make beyond any doubt you've got enough space to accommodate it securely, considering warm dissemination and ventilation.

5. Security Safeguards:
Guarantee appropriate wiring and establishing to avoid electrical dangers. In the event that you're not recognizable with electrical work, it's prudent to look for help from a qualified circuit repairman.

6. Proficiency and Regulation:
Be mindful that employing a step-down transformer may present a few wasteful aspects and voltage vacillations. Check the determinations of the transformer to guarantee it gives steady yield voltage inside an worthy extend.

By considering these components and guaranteeing legitimate establishment, you ought to be able to utilize a step-down transformer to adapt your DC control supply for utilize with a 120V power source. In any case, in case you're unsure about any perspective of the method, it's continuously best allude to">to allude to with a proficient circuit repairman or specialist.

 

[BradtheRad]

There are transformers (or auto-transformers) constructed to operate in either direction, step up or down. I have one rated 300 Watts. It has taps (with thumb-nut terminals) so I can hook up any arrangement of:
110, 120, 130 VAC to serve as either supply or output,
with the opposite being 220, 230, 240.
In the US I have used it to drop 120V to 60, and run my window fan at slower speeds.

I agree the topic here requires a step-up function, not step down.

 

[Gaber Mohamed Boraey]

Generally, as long as its done on the mains AC side and the step-down transformer is sufficiently rated, you should be OK. Things to be careful of are the power rating and AC mains frequency. Most 120V countries use 60Hz mains and most 220V countries use 50Hz, there are small differences in the transformer design to cater for the frequency difference. If your power supply has a power rating on it (Watts or VA), use a transformer with at least that rating and preferably add at least an extra 10% to allow for inefficiency in the transformer itself. Using a step-down transformer with even higher ratings is not a problem.

Brian.

Right I agree

--- Updated Mar 28, 2024 ---

I agree the topic here requires a step-up function, not step down.

For what step up?

 

[D.A.(Tony)Stewart]

In case you were wondering, voltage transformers are reversible and the V/L volts per Henry ratios are the same on both sides which affects no-load excitation currents and mutual coupling losses. The difference in frequency also affects this but generally not significant unless trying to utilize maximum power at the same temperature.

So you can use a 220 to 120 TXFMR in reverse to power your 220 Vrms supply from 120 Vrms. Within safe margins for temp rise. But 240:120 all depends on utilization and spec details.

 

[Gaber Mohamed Boraey]

I have a DC power supply made for a 220v country but I have 120v where I live. Can I just wire-in a step-down transformer between the mains and its internal power supply or is there more to it?

How much watt does your dc power supply need?, and how much the step down transformer handle ?