Blocking Diodes

[Sudden]

Hi,
How do I calculate the correct blocking diode?
I am trying to stop voltage going to a DC socket when it is not in use and to a battery set when a power adaptor is plugged into the dc socket . I am using a dc voltage of 9.6 with 1A current. This for a PMR Radio converted to amateur radio use.

 

[davenn]

Hi there also a ham radio op this way

I am trying to figure out your meaning. draw a pic and post it with the various bits to the puzzle and how / when they need to be connected

Dave

 

[Sudden]

Hi Davenn,
I have put together a diagram for my small project. As you can see no input socket is shown this because I can’t find a suitable symbol for it.
The battery shown within the blue square can be taken off of the radio and if left disconnected then the terminals of the battery and radio are exposed to touch. My idea is to leave the battery on the radio but disconnected from the radio when using the power adapter via the dc socket otherwise the battery and the adapter will both supply voltage at the same time.
The diodes will block voltage from the battery going to the socket and voltage from the socket going to the battery.

 

[duke37]

The diodes in the negative leads are not needed and in fact are the wrong way round and will stop the circuit working.

 

[davenn]

The diodes in the negative leads are not needed and in fact are the wrong way round and will stop the circuit working.

Agreed, take out the 2 negative lead diodes, not needed
But that still doesnt disconnect the battery from the radio when the main supply is used. A relay across the main supply with NC contacts would keep the battery in cct till the main supply and relay was energised. Then the NC contact would open and disconnect the battery.

see how that suits ya

cheers
Dave
VK2TDN

 

[Sudden]

Hi Davenn,
I will look into that idea. It might come down to lack of space to fit the relay.
Sudden

 

[davenn]

Hi Davenn,
I will look into that idea. It might come down to lack of space to fit the relay.
Sudden

there are some VERY small relays available have a look around

Dave