very low voltage multivibrator

[jarvis]

I need a multivibrator circuit to drive two alternating(1hz) loads of 800ma using a 1.5 AAA cell. It needs to fit in a space about two inches by 1/2 inch and be as low as possible(1/4" to 3/8" max). Preferably I would like to use all surface mount components. I've been working with a Zetez zsct1555 timer but can't seem to get it to trigger once the capacitor charges. It is the basic 555 timing circuit with Ra=220, Rb=3200, and Ct=100uf. I have the timing circuit driving output circuitry, but have disconnected it for testing. I am testing it with a variable power supply. Maybe my Ct leakage is too high? How do I tell? Maybe a two transistor multivibrator would be better, but I can't seem to find one that will opperate with my specifications for a reasonable cost. Any help would be greatly appreciated! Thanks!

FYI
I am building a swimming fishing lure using this circuit and may need volunteer product testers if you are interested.

 

[BrianR]

NS Semiconductors make an LED Flasher Chip (LM3909 from memory) and it will run off 1.5V and deliver surprisingly high peak load curreents. As for delivering 800mA loads from a AAA cell, that's asking a lot of the cell, even for short pulses. Battery life will be short as AAA nicads (which are the best for high currents), generally have a capacity of only 180mAH.

 

[jarvis]

Thanks for responding to my post. I will try to keep my current as low as possible, I might only need 400mA which the AAA should be able to produce for an hour according to Energizer and Duracell's web sites. I have looked into the 3909 from National and it is discontinued. Also I can't seem to even find it in surface mount,if they ever even made it. I would like to use something still in production. I think the tsc1555 would be my best bet but I don't have any experience with this chip. I have the data sheets, but they don't seem to be providing the answers I need.

 

[nbucska]

Your E-mail addr ? <nbucska@pcperipherals.com>

 

[jarvis]

NBUCSKA

My e-mail is <ben_englund@techemail.com>

 

[jarvis]

All readers,

Please also see &quot;low voltage 555 Zetex zsct1555&quot;

Thanks