Maybe you could implement the joule-theif circut to jump in when the voltage gets to low.. Like to suck the battery real dry

 

Maybe you could implement the joule-theif circut to jump in when the voltage gets to low.. Like to suck the battery real dry

Thats a good one to use, but I think the MC34063 can already do that. Should have 95% efficiency as well.

 

Thats a good one to use, but I think the MC34063 can already do that. Should have 95% efficiency as well.

Wow nice litle thing. but i see it's input starts at 3 volt so for small flash-lamps maybe there is an other chip?. The ones i use often go with 2 or 3 1.5v batteries.

 

The reason for a 9v is because I want my circuit to last for a long time, whereas the PIC is around 3v

Why are you putting three 3 volt cells in series to get 9 volts then taking that back down to 3 volts again if the device being powered can be ran off of one 3 volt cell?

Is there a problem with just putting all three 3 volt cells in parallel opposed to series and running the device directly off of them that way in order to get a 3x longer run time without any extra components?

 

Is it only after this regulator that resistors would be fine to use???

You want to maximize battery life by minimizing current draw.

Place any and everything where the current draw is the least.

 

You want to maximize battery life by minimizing current draw.

Place any and everything where the current draw is the least.

How do you mean that? Like use things that draw little or try to regulate on the negative side of the big current consumers like the lamp motor etc?

 

Why are you putting three 3 volt cells in series to get 9 volts then taking that back down to 3 volts again if the device being powered can be ran off of one 3 volt cell?

Is there a problem with just putting all three 3 volt cells in parallel opposed to series and running the device directly off of them that way in order to get a 3x longer run time without any extra components?

Well, do you prefer parallel or series for 3 coin batteries? Maybe Im wrong but Im assuming that even if you put 3 3v coin batteries together to make it 9v, they will die off around the same time as when using a single 3v coin battery?

If I was to use just a single 3v coin battery, how long do you think it would last when the entire device is on pulsating frequencies (I have 2 pulsating LED's and 1 pulsating crystal oscillator) instead of constant voltage? I'm thinking to extend the life of the device for 3 to 5 days (being used between 8 to 12 hours a day) with batteries and at the same time lower the current. Still trying to figure this out myself. So far the current drawing out is between 0.01 to 0.05A.

 

I agree with tcmtech. Putting the cells in series to get 9v and then dropping it back to 3v will only waste energy. Wasted energy means less battery life. Think of it like this. The 6v extra has to go somewhere, either in a resistor, linear regulator, buck regulator, switching supply… You want to minimize these losses.

One way to minimize the losses is to only supply 3v. No extra volts to waste thus wasting battery life.

I also agree with wiring the three batteries in parallel to get 3x the life.

Why are you putting three 3 volt cells in series to get 9 volts then taking that back down to 3 volts again if the device being powered can be ran off of one 3 volt cell?

Is there a problem with just putting all three 3 volt cells in parallel opposed to series and running the device directly off of them that way in order to get a 3x longer run time without any extra components?

 

I agree with tcmtech. Putting the cells in series to get 9v and then dropping it back to 3v will only waste energy. Wasted energy means less battery life. Think of it like this. The 6v extra has to go somewhere, either in a resistor, linear regulator, buck regulator, switching supply… You want to minimize these losses.

One way to minimize the losses is to only supply 3v. No extra volts to waste thus wasting battery life.

I also agree with wiring the three batteries in parallel to get 3x the life.

Thanks for the reply. I found a quote for parallel batteries:

"Connecting in Parallel
When connecting in Parallel you are doubling the capacity (amp hours) of the battery while maintaining the voltage of one of the individual batteries. This would be used in applications such as laptop batteries, some scooters, some ups backups, etc. Use a jumper wire between the positives of both batteries and another jumper wire between the negatives of both batteries. Connect your positive and negative wires to the same battery to run to your application."

So in parallel, this means that I am using voltage from only one of the batteries, but what is happening to the other 2 batteries? Are they just supplying voltage to the battery I am getting voltage from or are they waiting in line to get used up? This i show I am understanding it.

 

Thanks for the reply. I found a quote for parallel batteries:

"Connecting in Parallel
When connecting in Parallel you are doubling the capacity (amp hours) of the battery while maintaining the voltage of one of the individual batteries. This would be used in applications such as laptop batteries, some scooters, some ups backups, etc. Use a jumper wire between the positives of both batteries and another jumper wire between the negatives of both batteries. Connect your positive and negative wires to the same battery to run to your application."

So in parallel, this means that I am using voltage from only one of the batteries, but what is happening to the other 2 batteries? Are they just supplying voltage to the battery I am getting voltage from or are they waiting in line to get used up? This i show I am understanding it.

No no its more like you put all posetive together and also all negative so it commes to be one big happy battery.
It should be "Connect your positive and negative wires as it would be one battery to run to your application."
serie would be +((3v battery 1Ah))- to +((3v battery 1Ah))- to +((3v battery 1Ah))- = 9v 1Ah
but paralell would be .. well all + together and all - together = 3v 3Ah

 

If you want to pull a plow with horses, two horses can work twice as long as one horse (parallel).

They don't suddenly start plowing twice as fast (series).

 

No no its more like you put all posetive together and also all negative so it commes to be one big happy battery.
It should be "Connect your positive and negative wires as it would be one battery to run to your application."
serie would be +((3v battery 1Ah))- to +((3v battery 1Ah))- to +((3v battery 1Ah))- = 9v 1Ah
but paralell would be .. well all + together and all - together = 3v 3Ah

Very well explained.

 

If you want to pull a plow with horses, two horses can work twice as long as one horse (parallel).

They don't suddenly start plowing twice as fast (series).

Understandable now. Thanks!