Hi,

I have a requirement for 3 stages of a project which I am upgrading.

Stage 1 - Take a 12V 7Ah battery and double the voltage,

Stage 2 - Charge a capacitor with the 24V result of stage 1

Stage 3 - use the stored voltage in the capacitor and send a pulse (min 4msec) using an SCR or Triac or ????.
This stage will need to be repeated up 32 times as 32 different lines will need to have a pulse sent. so 32 individual SCR's etc.

The pulse amps must be more than 800mA.
Most basic Circuits possiable as they need to be robust.

I currently perform this task with just the battery and a lots of toggle switches but the pulse is not as good as it could be, distance can be a problem. Several other systems use the description as above but are very expensive to purchase so I am going to try to build my own. (or try to)

I have approached it in these stages as I can improve the model as I go.

So there you have it any help would be great.

Best Regards

Emmy

 

LM2586 will do the doubling and seems simple
http://www.national.com/ds/LM/LM2586.pdf#page=23

For the capacitor charging you'd need to monitor current flow to the capacitor, this can be done with a low ohm resistor. When the current stops flowing you then trigger your discharge device.

 

mrmeval,

Looks great thanks for that.
My only question is on the stats page 23 to be exact it states only .6A @ 24V
I require an absolute minium of .8A @ 24V is there some way I can do this with this device. If I can't get the Amps the thing won't go bang.
ps I am fireing fuse heads for (fireworks)

 

mrmeval,

You have put me on the right track.

LM2588 will do the job I think.
I will invest in the componets tomorrow and see if I can get it working.
The move to stage 2

Thanks

 

No problem. I saw the 5amp one but thought the 3amp would work. Do you read that as not producing 3amp? Oh, BTW I am getting an RSS feed and for some reason did not see your response I'm not sure why. Guess I should check on email notification.

 

The site that you reffered to him is good but it could only range from a minimum input of 5V to be multiplied or doubled (I saw on that page..). I'm having difficulty with my project., I only have a minimum DC input of 0.6 up to a maximum of 4.5V dc. how can I ever multiply our double its voltage rating?? please help..

 

Beannie,

I solved my voltage double problem with this

http://www.jaycar.com.au/productView.asp?ID=AA0264&keywords=step+up+converter&form=KEYWORD

Works a treat !

Although the input voltage you are quoting may be a little low for this unit.

Emmy

 

As I understand it ,800mA is firing current and is determined by cap size , charged V, & cap & line resistance, not power supply current rating. Power supply is disconnected from cap. at time of firing? I designed and used cap. discharge "blasters" using early SCR's around 1957.