Oh, that's what you meant -- I was hoping these would work with a=20
positive-only swing, but adding an h-bridge should be no issue.

Thanks,
-Neil.


On 11/20/2015 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 w=
ire
>>>>> really likes AC, like push and pull that is fairly well balanced. DC =
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 spec =
is
>>>>>> 90-120V at 1Khz-2kHz.  Couldn't I use a high-voltage LED driver for =
this
>>>>>> purpose?  Something like Fig 8 here...
>>>>>> http://www.monolithicpower.com/DesktopModules/DocumentManage/API/Doc=
ument/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 swit=
ch
>>>>>> on/off that quickly.
>>>>>>
>>>>>> Anyone know of a simpler way to do this?  Or maybe even a very thin =
(say
>>>>>> few mm tall) transformer that can work for this purpose?
>>>>>>
>>>>>> Cheers,
>>>>>> -Neil.

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