I'm looking for a circuit that could drive ~1 Foot of EL Wire.

EL Wire is a-bit strange in that it requires high voltage AC at a high frequency to work. Also its acts like a capacitor, FYI.

It needs to be driven at about 60 Volts 400Hz (although it may work with a lower frequency, it will be dimmer). (Current draw 0.45mA)

Also just the keep things interesting, I intend to drive it from a single 1.5 V battery.
Built from as few parts as possible, and no surface mount components.

Could a blocking type oscillator generate a high enough voltage from 1.5 Volts input? (efficiency would be nice, but not critical)

Does any one know of any such circuits that could be modified to work in this fashion?

 

Very interesting!

The low voltage would be a challenge.

Is 400Hz the recommended frequency, or is higher frequency acceptable? Reason I'm asking, is I picture an oscillator circuit driving a step-up transformer; a higher frequency would enable the use of a smaller transformer.

You do not get something for nothing in electronics, or anywhere else. If the boost to 60V@45mA were even close to 100% efficient, it would require around 3A current, which would suck a battery dead fairly quickly. There would be quite a loss just in the semiconductors alone. Typical PN junctions have a voltage drop of 0.6V across them, even at minimal loads. When you're talking AMP loads, the drop goes much higher. MOSFETS have a far lower drop, but would require boost circuits to get voltages high enough to turn their gates on and off.

Just brainstorming here.

 

If you just want to get it done and working, then just get a prepackaged EL Driver. They are designed to power small backlights, but you should be able to find one that can handle your EL wire.

http://www.supertex.com/feature_elfamily.html

http://www.micrel.com/page.do?page=product-info/el_drivers.shtml

www.maxim-ic.com

Rohm

St Micro

I didn't see a lot of input voltages down to 1.5V, you might have a bit of trouble with that one.

Steve

 

Is 400Hz the recommended frequency, or is higher frequency acceptable?

If the boost to 60V@45mA were even close to 100% efficient, it would require around 3A current, which would suck a battery dead fairly quickly.

450.0 microampere (µA)

Thats 27 mW of power.

According to the specifications; the highest listed frequency is 4000 Hz. (with a corresponding shortened lifetime) -- in fact I'd rather even lower than 400Hz...

Also I suspect that a true AC sine waveform is likely unneeded, so any kind of AC oscillation would do (sawtooth, square, whatever).

What types of circuits can generate this level of voltage?

 

If you would have looked into the links I gave you, you would see how the inner workings of the IC accomplish the task. They basically use a boost converter to power a half-bridge. So, there is a voltage loop for the boost converter with PWM and a single FET. Then, this voltage powers the half-bridge, which is also PWMed to approximate a sinewave.

Steve

http://www.supertex.com/pdf/datasheets/HV860.pdf figure 1

 

Ahh thank you, I'll still need to decipher what each block does exactly.