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1/2 AA 3.6volt (less than) $1 buck ea. - /w catch.

Trash80toHP_Mini

NIGHT STALKER
It looks like the LEDs stay on continuously in that pic. Is that the case or were they flashing and you caught a few on during exposure?

 

uniserver

Well-known member
They where flashing.

By shorting one of the water sensing leads to the leg of the LED, it will say on continuos.

However the the battery strains to keep up with the energy consumption of the LED, The circuit was energy optimized

with this high-output LED to be flashing. The LED acutely kicks on using power right from the 16v 10uf tantalum cap.

Removed and Wired one of the LED's up to my 6v with a pot, and man this thing has some serious light output.

 

Cory5412

Daring Pioneer of the Future
Staff member
A 3V battery is not sufficient. I've tried it before.
Long ago in a universe far, far away, I popped a pair of AAs into a Performa 475 I had. Worked flawlessly for me, the machine held time and turned on without employing the PizzaBox PowerToggle. I don't know if I'd recommend it as a long-term solution, but I also don't know if I'd go buy more than a hundred batteries which require physical modification before they can be installed in a Mac.

 

Unknown_K

Well-known member
If a battery reads 3V with no draw (volt meters don't use much for the load to calculate voltage) then it might dip lower when in actual use. Once batteries start dropping in measured voltage from design voltage they are pretty much junk.

Are you planning on reselling them or do you have 100 old macs with dead batteries? I have 10 or so new PRAM batteries in stock so I am good for a few years.

You can get 5 new ones for a little over $2 a piece shipped on ebay, less damage to the hobby budget.

 

MidnightCommando

Well-known member
Just fwiw - that SOIC-8 isn't a small 555.

Don't try and use it as a 555.

It's a driver IC for the LED, most likely. Similar circuitry exists in all my multimode high power LEDs.

... Besides, for simply flashing an LED, you don't need a 555. One cap and a transistor is pretty much all you need. ;)

 

LCGuy

LC Doctor/Hot Rodder
*shrugs* I ran a 3V camera battery in an LCII for years, it was a bit bigger than the normal PRAM batteries, but I never had any issues with it.

 
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