I added the D1(1N4001) again, in the very beginning that I had been concerned about that diode to avoid the reverse voltage from the bat1 to photocell(c to e of Q1), and the R8 is reserved for when the Q1 not easy to turn off, and then the b of Q3 can't get the current from c to b of Q1.

 

Great thank you Scott. I am guessing that sw1 is the photocell?

 

The thing under the switch is the solar collector. We are having a difficulty with language. I can understand why Scott uses a word differently from me. He is translating from a different language. Please try to accommodate me in this thread.

 

Great thank you Scott. I am guessing that sw1 is the photocell?

The Sw1 is a real switch, it can let you to decide you want to use the solar cell or not.

Or you can choose to in series between the Bat1 and 555, or you want to use two switches.

 

I have a couple questions on Scotts diagram.

1. R2 is a 70K . I have a 68K will this work?
2. C2 is a 0.01uf I have a .1uf ceramic or do i need a .1 aluminum?

 

I have a couple questions on Scotts diagram.

1. R2 is a 70K . I have a 68K will this work?
2. C2 is a 0.01uf I have a .1uf ceramic or do i need a .1 aluminum?

About the 70K, that is my mistake, the original value is 470K, the flashing speed close to 1 times/0.7sec, if you using 70K or 68K then the flashing speed will become more fast, it will close to 1 times/0.1sec.

The pin 5 of 555 is used to change the Threshold voltage, normally when you using 0.1uf or 0.01uf that they don't have much different, even you take it away and the IC still working, you can try to using different value to see any change.

 

Thank you Scott! Should have this built by Friday and post how it goes.

 

Why add all of that extra stuff for a photocell when the solar cell can charge the battery and when the voltage goes low at night, it can power the 555 circuit?

All you need is a diode and a PNP transistor to turn the circuit on.

 

Burger2227 I have tried that already to no avail. Unless I was doing something wrong. I could get the led flashing but not turn it off.

 

How did you try to turn it off? The solar panel would need a lot of light.

Something like this:

Resistors to PNP base could be increased or decreased a bit. More than 1K may let it drain less solar power.

 

timer like this but with 6 leds. I did solar panel to diode to battery pack. Then tried pos to pos and neg to neg nothing. Tried neg to reset . I have pretty much tried every combination .

 

ARRGH! Stuck me on last page. How old is this forum software?:

Resistors to base are not critical. More to common uses less solar power. May not need it at all.

A Shottkey diode has less voltage drop. PNP could be 2N5401 or 2N2907.

 

Thanks I'll give that a try. Post back soon

 

How did you try to turn it off? The solar panel would need a lot of light.

Something like this:

Resistors to PNP base could be increased or decreased a bit. More than 1K may let it drain less solar power.

In your modified circuit, when the solar cell is no power output, the current of bat1 will flows through Vbe of Q1 and R7 to solar cell.

 

Perhaps another diode is in order. I'm just guessing on exact values. I've used similar circuits, but the battery charge was not critical either.

If you know a better way then feel free to post it. I didn't see a reason not to use the solar panel as the switch rather than have redundant duplication.

With 6 LED's at 15 ma, the solar panel may never be able to keep the battery up, but it can work as the on switch.

 

I have this circuit together. If i take out the 1k in the beginging that connecrts before D1 and - The leds light in the day and off when covered. Which is backwards. Also the leds do not run from the battery pack nor does it flash . I have posted some pics to see if you see anything wrong. I know its a mess

 

Better pics

 

Hello,

One of the resistors will be shorted by the strip inside the breadboard:

Bertus

 

Ok fixed that just ran the resistor to the led and took out the orange wire.Still have nothing

 

Can't trust ya now, send more pictures...

Show us the 555 running the LED's without anything else. Then add the transistor as a switch to turn it on.

IE: maybe something else is broken already.