problem with the 2k VR in 20vac.........

[adax811]

problem with the 2k VR in 20vac.........

the VR is modified to control the 20V 50hz vibrator......

the VR easy to get burned after awhile...

i need an alternative rugulator circuit to replace the VR but the S-wave need to smooth like using normal high Watt VR....



comments are welcome......

thx.



adax811.

 

[Hero999]

You haven't mentioned the current requirement.

It sounds like you've exceeded the power dissipation rating of the variable resistor.

You need a high powered variable resistor, also known as a reostat.

Another option would be to add a variac on the primary of the 20V transformer.

 

[adax811]

You haven't mentioned the current requirement.

It sounds like you've exceeded the power dissipation rating of the variable resistor.

You need a high powered variable resistor, also known as a reostat.

Another option would be to add a variac on the primary of the 20V transformer.

the ampere for the vibrator is 0.7A (i applied clamp meter to it) when i supply full 20VAC to the vibrator........
in addition, can u provide me where to get the parts, which i'm living in asia......

 

[Ubergeek63]

a switcher. since you already have a since wave you do not want to regulate it, just down convert it.

I do not normally recommend 555s and the like as switchers because they can not regulate, but you do not want it to regulate. A simple 555 PWM, a FET, an inductor, and a capacitor.

Dan