Min operating voltage?

Paul Baker

I think Chip mentioned this in the seminar, but I can't remember it. What is the minimum voltage the propeller can be run at? The reason I ask is Electronic Goldmine has .6F Polyacene batteries (really more of a supercap)·that are 3V for dirt cheap. If the propeller could be run at 3V, these could make a great battery backup.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
1+1=10

Gadgetman

They don't give any mA ratings, but they look interesting...

How come I've never heard about Electronic Goldmine?
The site's an absolute goldmine of parts...



▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Don't visit my new website...

Tracy Allen

Hi Paul,

Brownout voltage at room temperature came out at around 2.7 volts on my single point sample. The Propeller was running quite nicely at 3.0 volts, although Chip would have to comment on how consistent or reliable that might be. Of course, you don't want to operate _too_ close to brownout.

Unlike the SX, the current does not increase in brownout or reset, so it won't immediately bottom out your backup power source. I bought a few of those Polyacene capacitors from Goldmine a year ago. I usually reach for a lithium cell for slow self-discharge and long life, but these supercaps (~0.6 farad, they say), could be great for backup when a primary power source is usually available. Good idea. I bet they would work okay at 3.3 volts too, only 0.3 over rating.

Here is that thread, where Chip had an interesting followup on the design of Propeller.

[noparse][[/noparse]urlhttp://forums.parallax.com/forums/default.aspx?f=25&p=1&m=120685#m120866

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com

Paul Baker

Gadgetman said...
They don't give any mA ratings, but they look interesting...

How come I've never heard about Electronic Goldmine?
The site's an absolute goldmine of parts...

The reason the mA isnt provided is that they are technically capacitors with a much higher charge density than electrolytic or even aerogel. As such there really isnt a limit on the mA. I read through the patent that covers the technology and it's just powdered carbon and resin thermally set in anerobic conditions. In the process the resin turns into an acene, hence its name. I understand the process, but I dont know what an acene is or why it's special.

Ive got a whole list of surplus suppliers if you're interested, EG is one of, if not, the best.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
1+1=10

Post Edited (Paul Baker) : 5/6/2006 2:10:44 AM GMT