Can I use any 9v ad...
 

  You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more

[Closed] Can I use any 9v adapter or do mA matter?

9 Posts
6 Users
0 Reactions
67 Views
 csb
Posts: 3288
Free Member
Topic starter
 

I have a baby monitor that charges from a holster. The plug adapter supplies 9v and 300mA. The wire has come loose.

i have a spare 9v adapter, but it supplies 1.5A.

I've read that as long as enough A is supplied it would work. Will I die?


 
Posted : 21/12/2015 8:30 pm
Posts: 16346
Free Member
 

Should be fine. There's a risk that it is more than just a power supply and has some charging smarts in it, though.


 
Posted : 21/12/2015 8:34 pm
 csb
Posts: 3288
Free Member
Topic starter
 

So if I cut and wires, connect them in a 'just testing' fashion, and give it a go, will it be obvious if the adapter had cleverer innards than just a 240-9 volt adapter?


 
Posted : 21/12/2015 8:48 pm
Posts: 0
Full Member
 

some cheaper adaptors only put out the rated voltage under load, if you've got a multimeter I'd check the voltage when it's only having 300mA drawn - it could be quite a bit higher


 
Posted : 21/12/2015 8:52 pm
 csb
Posts: 3288
Free Member
Topic starter
 

I don't even know what a multimeter is. I think I'll leave it alone....


 
Posted : 21/12/2015 9:02 pm
Posts: 0
Full Member
 

You will be fine. It's a problem if you want to run a gadget that needs 1.5A with a 300mAh supply but I'm the other way round. Just means you have plenty in reserve.

Have just sat a technical radio exam that covers reasonably advanced electronics...


 
Posted : 22/12/2015 4:47 pm
Posts: 11486
Full Member
 

Double check whether the existing lead is positive pin or negative, there is no standard so you need to ensure you don't switch the polarity.

Lots of generic chargers come with a switch or you can turn the pin around on the end of the lead to switch the polarity.

[img] [/img]


 
Posted : 22/12/2015 6:15 pm
 csb
Posts: 3288
Free Member
Topic starter
 

The wire is hard wired into the holster. So I'd planned to cut off the bad adapter, and the connector from the new adapter, and initially splice the wires together to test it, before using proper connectors later. Would a +ve/-ve mistake blow it up?


 
Posted : 22/12/2015 6:36 pm
Posts: 0
Free Member
 

Incorrect polarity could break it, you won't know until you actually do it 🙂 Get a cheap multimeter, google will tell you what they are.


 
Posted : 22/12/2015 6:40 pm
 csb
Posts: 3288
Free Member
Topic starter
 

Thanks all.


 
Posted : 22/12/2015 7:33 pm

6 DAYS LEFT
We are currently at 95% of our target!