The star on the HP-15C's display screen

[Dave Frederickson]

(09-25-2015 09:52 PM)Bill (Smithville NJ) Wrote:  

(09-25-2015 09:09 PM)Dave Frederickson Wrote:  Edit: And 2196 volts would look like ...

Dave,

Thanks for posting this. Now I know what to do with all my old batteries.

Reminds me of when I was in grade school, I took a large transformer from an old TV and then made a half wave rectifier circuit to have DC volts. I then used it to recharge my 9 volt battery for use in my transistor radio. I found that 9 seconds would put a charge into the battery which would need to cool off before touching it. Ten seconds would cause the metal battery case to explode off the battery. The result was a battery case embedded into the plaster wall. A lot of fun and fond memories. Especially since I never succeeded in electrocuting myself - only in giving myself a lot of very strong shocks.

Bill
Smithville, NJ

It's from one of Dave Britten's old threads: What to do with a bunch of slightly depleted 9V batteries? kusmi posted it!

Ahh, yes, there were lots of popped circuit breakers at home when I was growing up. I had lots of fun teaching my son how to create a carbon arc with two #2 pencils and a suicide cord!

Dave