Bob, What about a DC-blocking capacitor? Sean On Fri, Nov 20, 2015 at 12:35 AM, Bob Blick wrote: > Hi Neil, > > No, square wave is OK. But if you have a DC source and you want an AC > square wave, you either need 3-terminal DC (positive, ground, negative) > and two switch elements, or an H-bridge. Either one will allow you to > alternate positive and negative excitation of your EL-wire. DC or DC > switched on and off will rot your EL-wire. > > Removing the rectifier from a photoflash and taking the output straight > from the transformer will be sub-optimal. The positive and negative > voltages are not balanced because the transformer is driven by one > transistor(with corresponding weird duty cycle. It will work OK but is > hard on the EL-wire, which doesn't last all that long anyway. > > Best regards, Bob > > On Thu, Nov 19, 2015, at 09:13 PM, Neil wrote: > > Oh, you mean sine-wave then I guess? > > > > > > On 11/19/2015 11:40 PM, Bob Blick wrote: > > > Switching it on/off is not AC. > > > > > > BB > > > > > > On Thu, Nov 19, 2015, at 07:14 PM, Neil wrote: > > >> Hi Bob, > > >> > > >> I was suggesting that I'd generate DC with the LED driver and then > > >> switch that on/off rapidly to get the 1KHz-2Khz AC (though square > wave). > > >> > > >> Cheers, > > >> -Neil. > > >> > > >> > > >> On 11/19/2015 12:46 AM, Bob Blick wrote: > > >>> Hi Neil, > > >>> > > >>> I've experimented a bit with this, and one thing I found is that EL > wire > > >>> really likes AC, like push and pull that is fairly well balanced. D= C > and > > >>> chopped DC don't work very well. > > >>> > > >>> Best regards, Bob > > >>> > > >>> On Wed, Nov 18, 2015, at 08:59 PM, Neil wrote: > > >>>> So I've got an EL driver that I want to use for a wearable, but it= 's > > >>>> bulky for that purpose, and I need something very thin. Seems the > > >>>> battery and transformer are the larger parts of the whole driver > > >>>> module. I decided to redesign it with a LiPo, but it seems that > all the > > >>>> EL driver circuits I'm finding have transformers. The EL-wire spe= c > is > > >>>> 90-120V at 1Khz-2kHz. Couldn't I use a high-voltage LED driver fo= r > this > > >>>> purpose? Something like Fig 8 here... > > >>>> > http://www.monolithicpower.com/DesktopModules/DocumentManage/API/Document= /getDocument?id=3D3473 > > >>>> > > >>>> I'd still have to throw an oscillator in there to modulate the LED > > >>>> driver, so I'll have to experiment to see if the LED driver can > switch > > >>>> on/off that quickly. > > >>>> > > >>>> Anyone know of a simpler way to do this? Or maybe even a very thi= n > (say > > >>>> few mm tall) transformer that can work for this purpose? > > >>>> > > >>>> Cheers, > > >>>> -Neil. > > -- > http://www.fastmail.com - IMAP accessible web-mail > > -- > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .