Simple Metal Detector build, minus the 555 IC?

[THATguy]

http://www.instructables.com/id/Simple-metal-detector/step1/Schematics/

Can I build this without the 555 IC?
While still keeping it VERY simple (component-wise).

I will not be using an air core, it will be more of a pointer - Iron oxide core.

[McBryce]

Yes, if you use half of a 556!

How to you expect it to work without the 555?

McBryce.

[Gyro]

Replace it with two comparator ICs, a resistor chain, and RS flip-flop and a push-pull transistor stage. 

[Zero999]

Replace it with two comparator ICs, a resistor chain, and RS flip-flop and a push-pull transistor stage. 

You could use a quad comparator IC such as the LM339 and a discrete push-pull output stage: two comparators, as per the 555 schematic and the other two configured as an RS filp-flop.

[MK14]

http://www.instructables.com/id/Simple-metal-detector/step1/Schematics/

Can I build this without the 555 IC?
While still keeping it VERY simple (component-wise).

I will not be using an air core, it will be more of a pointer - Iron oxide core.

You CAN build it without the 555 IC.

In the same way, you CAN have a car without an engine or a house without a roof.
As long as it never rains, and you only want to drive, downhill, you will be fine.

But if you want the circuit to work as intended, then it needs the 555 IC, to make it work. Without it, you will basically end up with a non-functioning paper weight.

The 555 IC is a highly versatile, low cost/simple timer/oscillator, which creates the functionality needed to make your metal detector work.

[hendorog]

Just google for "transistor metal detector", there are many simple circuits.

e.g.
http://www.talkingelectronics.com/projects/200TrCcts/MetalDetectors/MetalDetectors-1.html

[THATguy]

Of coarse. IC's are made from transistors, duh!
I've got a stack of basic components lying around, but not too many IC's.

Thanks for the link too, really appreciate that.

[NottheDan]

Here's a model without 555 or transistors.

[Back2Volts]

Here's a model without 555 or transistors.

Very cool !