kit modifications

[Nenad]

Hi, I've found a metal detector kit at my local electronics shop, and am considering purchasing it as information source. I have a few questions though. For a given circuit design, how is the recommended supply voltage calculated. Also, can you use greater voltage to increase transmitter output without modifying the electronics? If no, is there a simple way of allowing larger batteries.
Any comments appreciated
Nenad

[Carl]

Re: kit modifications

The circuit is usually designed around a particular supply voltage. Increasing the voltage will generally not increase depth to any extent, and could mess up biasing and cause the circuit to stop working.

If you know what voltage the circuit needs and you want to use a larger battery, you could add a regulator between the battery and the circuit. A simple resistor+zener diode will work, although a true regulator chip (78xx) is better.

- Carl

[m w]

Re: kit modifications

also a higher voltage would destroy any ttl chips etc as they normally use a 5volt applied voltage.

I would not recommend altering the circuit.

you could experiment with different circuit designs using a spice program like electronics workbench or circuit maker.

your best bet for improving the device is making your own coils and experimenting with size, shape and number of turns.