Voltage difference

Thread Starter

burtonwisher

Joined Aug 9, 2011
4
I need some assistance with a voltage question I have.

I have built a circuit that uses a 555 and a 4017 to flash sets of LED's, and it's working perfectly (thanks to previous assistance), powered by a mini battery (MN21 for 12v or 28L for 6v), which I'm using becuase:
- The 555 needs at least 5 volts
- The model I'm using it in is too small to accomodate anything bigger, so a 9v PP3 is too big.

I now want to add another circuit to my model that uses a UM3561 chip to create a siren effect, but the technical spec states that it's maximum voltage is 3.6v, so I'm assuming that I wont be able to run it with my 6v or 12v mini battery.

However due to the lack of space I need to be able to run both circuits off the same tiny battery. Is there a way that I can do this easily and cheaply? Hopefully by adding just a small number of components for example?

The schematic of mt UM3561 circuit is attached for clarity.

Thanks in advance
 

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Bernard

Joined Aug 7, 2008
5,284
About 5 diodes or one 3V zenor, with 6V battery. What is the drain of the UM3561 at desired volume level?
A pie in the sky thought: assuming that sound effects are of short duration, cherge a .22F cap to 3V derived from 555- I tried it, 5V to 3V @ 40mA- but alas 555 seemed to run a little hot and I did not get back to it before needing board for something else.
 

Thread Starter

burtonwisher

Joined Aug 9, 2011
4
The MN21 (12v) is rated at 33mAh, and the 28L (6v) is rated at 160mAh. I am also open to other battery options if there are any, as long as it's small, i.e. no bigger than about 30mm long by 13mm diameter.

Thanks
 
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