ON/OFF switch for internal battery clip.

[steveyraff]

Hey guys,

I'm sure this is a silly question as it seems straight forward. I am building a pre-amp box for a customer. Its just a pre-amp with volume, high pass filter, and phase inverter switch. It is not a stomp box, ie no footswitch.

I've made these before, all running on standard 9v centre tip neg power supplies. However, this guy wants me to make a battery clip inside, as well as the DC power socket. I presume this means it will be ON all the time. Is there a very simple way of making a small on/off toggle switch for turning the battery on/off which will also turn the power LED on/off ? ?


Is there a simple wiring diagram out there for this?

Thanks!

[Aph]

[Mark Hammer]

Hey guys,

I'm sure this is a silly question as it seems straight forward. I am building a pre-amp box for a customer. Its just a pre-amp with volume, high pass filter, and phase inverter switch. It is not a stomp box, ie no footswitch.

I've made these before, all running on standard 9v centre tip neg power supplies. However, this guy wants me to make a battery clip inside, as well as the DC power socket. I presume this means it will be ON all the time. Is there a very simple way of making a small on/off toggle switch for turning the battery on/off which will also turn the power LED on/off ? ?


Is there a simple wiring diagram out there for this?

Thanks!

Traditionally, the method was a switched volume pot.  Turn it just a tad past 7:00 and you hear the click as the power is disabled.  Not knowing the pot value used for your volume control, I couldn't say whether this would be easy or hard to find.  But 10k, 100k, and 500k pot with integrated switches are not hard to find.

[steveyraff]

Do I need to put my battery snap negative (black) wire to a stereo input jack ring as shown on traditional layouts?

The reason I ask, is that I am wiring a preamp box up with no 3PDT foot-switch. Instead I have a SPDT toggle switch acting as a Power on/off switch.

So... I have the circuit 9v and LED positive both going to the SPDT middle lug, then a wire going from the 3rd lug to the DC jack postive lug. Going to the DC jack's ground lug I have the usual circuit grounding, and the battery snap black negative wire. On the spare lower positive lug the battery snap positive red wire. Doesn't this mean when the switch is in the off position it will not be drawing any power from either the Battery or the DC jack if a power cable is connected??

Sorry, don't normally make builds with both DC and 9v Battery power. 

[slashandburn]

Correct me if I'm wrong (I'm more than used to it) but I was always under the impression that this exact problem was the main reason we used the whole tip-negative, sleeve positive wiring scheme for our DC socket wiring.  It allows us to automatically dump the 9v battery out and away from the circuit as soon as a DC adapter is plugged in without the need for a switch.

Sorry if I've missed something more obvious in reading through the issue. I always thought three lugged DC sockets and tip negative wiring WAS the switch.

Edit: damn, I found the obvious thing I was missing
> Its not a stompbox

My appologies for wasting your time!

[RickL]

I think you can do it with a spst switch. This would be better with a diagram but here goes... (this assumes you are using a Boss style negative tip power supply.

Wire the black wire (-) from the battery clip and the ground lug of the power supply jack directly to the ground of the circuit.

Run the red wire (+) to the switched lug of the power supply jack.

Run the positive (unswitched) lug of the power supply jack to one pole of the spst switch.

Run the other pole to the + connector of the circuit.

When the spst switch is closed and no power supply is plugged in the circuit will be supplied by the battery, through the power supply jack and the spst switch. If you plug the power supply in, the battery + is disconnected and the circuit is supplied by the power supply, through the spst. Turn the spst switch off and no power gets to the circuit and neither the battery or power supply are connected to anything.

[steveyraff]

I think you can do it with a spst switch. This would be better with a diagram but here goes... (this assumes you are using a Boss style negative tip power supply.

Wire the black wire (-) from the battery clip and the ground lug of the power supply jack directly to the ground of the circuit.

Run the red wire (+) to the switched lug of the power supply jack.

Run the positive (unswitched) lug of the power supply jack to one pole of the spst switch.

Run the other pole to the + connector of the circuit.

When the spst switch is closed and no power supply is plugged in the circuit will be supplied by the battery, through the power supply jack and the spst switch. If you plug the power supply in, the battery + is disconnected and the circuit is supplied by the power supply, through the spst. Turn the spst switch off and no power gets to the circuit and neither the battery or power supply are connected to anything.

Thanks for taking the time to write that out. I think if I read it correctly, it is exactly as I have wired and described in my post - so I think thats how I have it right now. I just wanted to make sure that was correct and not draining the battery when the switch is in the off position. Thanks