Solar Pummer (using 74HC04)

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Krumlink

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I am looking for a simple circuit that charges up a couple capacitors (1000uf total) and then discharges them . I just want it to charge up until it can power a LED, so basically I am looking for a Pummer. It will charge up until it can light up a white LED. Any help? I am stuck. I bought a FLED and I tried making the FLED PUMMER, but I cant get it to work. Therefore, I want to make a Pummer using the 74HC04. (hex inverters with no schmitt triggers). If you have tips, let meh know!

If I can at least get a Good Solar engine, one that stores up enough energy (2.5-3V) and uses a FLED, I can get the LED circuit myself, but I need at least the Solar engine.

 
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You could replace the 74hc14 "PowerSaver Flasher" part of the circuit from this site:
**broken link removed**
With the 74hc04 based one from Bowden's site:
**broken link removed**
It should run nicely on 2V also.
 
Thank you so much! I have been looking frantically for somthing like this! You get respect from me!
 
Hey, my krumlink profile wont log on, so I have to use out of control (that's what quan means on the street, totally did not know that when I made this profile).

I found this Pummer, except that he uses a capacitor to increase the voltage. How can I do this with a single capacitor?

**broken link removed**
 
I did find this...
**broken link removed**

So if I attach the output of the solar power supply in series (+ power supply to - cap v doubler to + of pummer to - of power supply) it should work right?
 
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Ok I fixed it, I am going to try the Pummer circuit without solar for now, then try it with solar, and finally the Voltage increaser.
 
Two diodes across a capacitor won't increase the voltage. The two diodes limit the voltage across themselves and the capacitor they are across to 1.4.V.
 
Krumlink said:
So how did he do it?
Click to expand...
I can't see any diagrams for his pummers, but I suspect it is done the same way as the example I posted earlier:
**broken link removed**
In the above circuit (the part to the right), when pin 8 of the 74HC14 is low, the 22uF cap slowly charges up to 2V via the 100K resistor. When pin 8 of the 74HC14 goes high (2V) it lifts the negative terminal of the 22uF cap to 2V which means that the + terminal of the 22uF is now at 4V. Thus 4V is dumped across the LED and it flashes once brightly until the 22uF is discharged. Brett Hemes appears to use larger capacitors for a longer, brighter flash.
 
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I think with only a 2V supply, the output current of a 74HC14 inverter is a low current. With a 3V supply it is much higher.
 
Ok, I will wire up 2 3V 25 ma in parallel to give out more Milliamps just to be safe.

Thanks

EDIT: I looked up charge pump, and I know how this works!

I will add a 1000uf cap to it for added voltage increase.
 
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I found a Philips article that spec's the typical output source current from a 74HCxx device is a whopping 7mA when its supply is only 2V. An LED is very bright with 25mA.

The "powersaver" circuit uses a Schmitt-trigger oscillator to charge a 22uF capacitor to 2V then the output switches it in series with the 2V supply to drive LEDs that need more than 2V. Since the 74HC14 has a typical output current of 7mA and the duty-cycle of the oscillator is about 50% then the LED glows diimly with an average current of only 3.5mA.

2V is when a 3V battery is nearly dead. I would parallel 5 of the inverters in a 74HC14 to charge the 22uF capacitor and drive the LED with much more current to make it nice and bright. Then I would add a diode in series with a resistor to make the oscillator blink the LED on for a very short time to save power.
 

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wow 7ma? thats like LS series power!

I am using the 74HC04 Circuit, so that is somthing else to consider. I was going to parallel 2 Inverters per part in the schematic above.
 
I use a 74HC4017, a transistor (for PWM brightness control) and 4 paralleled 74HC14 Schmitt-trigger inverters (to blink each LED for a very short time) to drive the bright red LEDs in my Ultrabright 3V LED Chaser project.

I use a 74HC4017, a transistor and a 74C14 to drive the bright blue LEDs in my 6V Ultrabright LED Chaser project.

I use a 74HC132 and 2 transistors to drive the bright red LED in my (3V) Plants Watering Watcher-2 project.

The AA alkaline cells last for months because each blink is for a very short time. The chasers chase around a few times then have a pause before chasing again.

The 3V ones still work fine when the battery voltage drops to 2V and the 6V ones work fine until the battery voltage drops to about 3.5V which is the LED voltage.
 
Ok, I have thought somthing out. i am giong to build a Solar Charge pump using preferably a Maxim Charge pump, but I need one that will be easy to connect up using a 3V 25ma Solar panel. I can parallel more if needed, but preferably a 8pin one.
 
My solar garden lights use one 1.2V Ni-Cad cell and a voltage stepup circuit to drive the fading red, green and blue LED. One stopped and I reverse-engineered its circuit so I could find and replace its shorted diode.
 

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