Working battery device turn into powersupple + battery device - Page 1
Forum section: electronics / beginners

author: Savetheday
author_rank: Regular Contributor
timestamp: October 04, 2015, 10:48:24 pm
content: Hi everyoneI would like to change my 9 Volt battery device into +9V powersupply connection device?Even if I use 9 volt battery i would like to connect +9v powersupply and at the same time recharge my 9V rechargeable battery.Is it possible with paralel connections? I have a 2 transistors 2N3906 2N3904 near by battery cable connection.Thanks.

author: JoeB83
author_rank: Regular Contributor
timestamp: October 04, 2015, 10:53:47 pm
content: Unfortunately this is a very vague description, can you give us more information like pictures, a schematic, model numbers, etc?

author: Savetheday
author_rank: Regular Contributor
timestamp: October 05, 2015, 12:48:55 am
content: Quote from: JoeB83 on October 04, 2015, 10:53:47 pmhttp://shop.anatekcorp.com/clientuploads/directory/products/Blue%20ESR%20assembly%20manual_Jan%202015.pdfThanks.

author: bills
author_rank: Frequent Contributor
timestamp: October 05, 2015, 01:47:21 am
content: If I understand correctly the op wants to run this off a 9v power supply (wall wart) and charge the battery at the same time.Short answer is no not without a charge controller.

author: rdl
author_rank: Super Contributor
timestamp: October 05, 2015, 04:43:34 am
content: Simplest thing to do might be to add a DC power jack for running off a wall wart and buy an 9 volt NiMH charger and a couple of batteries. There are cheap battery/charger combos (under $20 US) on eBay.

author: JoeB83
author_rank: Regular Contributor
timestamp: October 05, 2015, 05:28:28 am
content: Quote from: bills on October 05, 2015, 01:47:21 amOk, that makes a lot more sense, thanks!You can run it from a wall-wart, just add the appropriate connector to the board, make sure polarity is right, and use it that way. As others have said, both charging and running the meter at the same time would require additional circuitry.

author: Savetheday
author_rank: Regular Contributor
timestamp: October 05, 2015, 09:54:16 pm
content: Quote from: JoeB83 on October 05, 2015, 05:28:28 amOk Im not going to recharge at the same time but do I need exactly 9 volts wall-wart or could it be like 5 volts or 7,5 volts 12 volts.How do we measure or know which intervals are we suppose to use?I want to thanks again and again.

author: JoeB83
author_rank: Regular Contributor
timestamp: October 06, 2015, 03:03:48 am
content: Chances are it'll work from a different voltage than 9V, but personally I wouldn't take the chance. I'd just buy a 9V wall wart.I guess if you really had to, you could use a 12-15V wall wart if you make a small, simple regulator circuit based around an LM7809. Check out this data sheet:http://www.farnell.com/datasheets/94418.pdfJust use the first circuit shown on page 18. Just the LM7809, two caps, and some wiring.

author: djococaud
author_rank: Regular Contributor
timestamp: October 07, 2015, 02:43:26 pm
content: As a dirt cheap solution, you can use this circuit...But make sure to choose R in order to have a low enough charge current to float the 9V battery without damaging it.If you use some low power Schottky diodes, the voltage drop should not be an issue...Djo.