Thank you.I know of ways around this, I'll get back with you.
Thank you.I know of ways around this, I'll get back with you.
Yes, that is the idea.I thought of powering the 555 from the two batteries. But I think I've read somewhere that it doesen't like more than 15v. Thats where the 7812 regulator comes in.
OK, read you post one more time. Could I use both batteries to power the LEDs (18v), and only one to power the 555 (9v)?
Are you suggesting to run 24 - 25 LED's all in parallel? That would be 20mA x 25 = 500mA. The LED array will draw more than 3W.OK. Dropping the 9v battery.
Trying out one more design...
The schematic in post #35, powered with 4 1.5v AA batteries, total of 6v.
The LEDs are single, with one resistor each.
How will that be for battery-life?
OrOK, so it boils down to 2 alternatives...
Alt 1.
Battery = 9v
2 LEDs in series, 12 strings, 24 LEDs
R=(9-(3.2 x2))/0.02 = 130 Ohm
0.02A x 12 strings = 0.240A
0.240A x 9v = 2.16 W
Battery life approximately 0.560A / 0.240A = 2.3 hrs.
Alt 2.
Battery = 6v
1 LED, 24 strings, 24 LEDs
R=(6-3.2)/0.02 = 140 Ohm
0.02 x 24 strings = 0.480A
0.480A x 6v = 2.88W
Battery life approximately 2.8A / 0.480A = 5.8 hrs
Correct or not?
Find one that holds 6 and instead of placing a battery in one slot, solder a wire from top to bottom.OK, thanks.
But where to find a holder for 5 AA batteries?
I will try to get 30ms, or maybe close to it.It is good that you have the duty-cycle of the on-time for the LEDs short. Then the battery will last for a long time.
You can reduce the on-time as low as 30ms but the LEDs will appear dimmed if you go below 30ms.
No transistors, no IRL2703, Just the 555 driving the LEDs. I'll guess I'm pushing the IC mA limit? I needed to put the LEDs on a separate board, or it wouldn't fit in the jar.As I understand this is a "new" design. How do you drive the LEDs this time. Also a good design idea to have the LEDs on a separate board. This way you may change the controller circuit easy say using a MCU without a total redesign
Thanks.Are you sure those bolts are sufficient? I would have gone with 1/2 inch. ...just joking.
Nice video and demonstration. How are you planing on keeping the device under water, a brick? or do you plan on designing a smaller housing, like from plexiglass.