New Homebrew Metal Detector

[zisme]

Hi Zisme,
I think it is better to use avalanche transistor, then mosfet .

Best regards

Have you tried any avalanche transistors? Do you have any part numbers that work?

What do you think about the ZTX413 ? It's in a TO-92 case and is good for 200 Ma. continous current with a 50 amp. peak pulse rating. See data sheet here: http://rocky.digikey.com/WebLib/Zete...ata/ZTX413.pdf

If this works, it would eliminate a lot of space used by the TO-220 FET.

Mike

[Seeker]

I have this transistor in sot-23,made by ZETEX, Ic-50A, Uc-150V, I think this is better for your detector, but you mast change schematic.I have made power supply for laser diode with this transistor.This is very good for UWB generator.You mast use HiVolt supply.

[Seeker]

I use ZTX415 Uc-200V , Ct-2nF for laser diode, pulse ~ 20ns, but this can be used for coil.I can't understand why everybody use analog schematic for time measurement?You can optimize method , if use counter to measure time for fadind of coil voltage.

[Geo]

:confused:




Do you have that manual scanned? If file is not bigger than a few mbytes, than o.k. send
it.
Best regards to you Geo

Hi Ivconic. I sent it to you via email. I have some problems with emails so did you received the file with the manual?
Regards

[ivconic]

Not yet...


Not yet...
my e-mail is [email protected]

anyway thanks a lot for good will..
regards

[omega]

Hallo,

how good is this detector when you compare it whit another projects like Hammerhead or Gary´s? I wanna built it but i wanna now if this detector is good or not.

Thanks,

omega

[marcelfff]

what capacitor have you installed, because i have a problem with 270 MHz.
hmmm pins are good i've checked c/b/a 1/1/0 please help my email [email protected]

[zisme]

what capacitor have you installed, because i have a problem with 270 MHz.
hmmm pins are good i've checked c/b/a 1/1/0 please help my email [email protected]

Which capacitor? 270 mHz.???? Please explain.

Mike :confused:

[omega12]

Can i use BC559C for Q2 because i can´t find MPSA70? What T can i use for Q2 for better amplification?

Thanks, omega12

[ma330]

22awg

hi to all
i want number wire 22awg . please give to

[omega12]

Hi,

27 Turns with 0.9 mm wire or 1.0 mm wire??? Q2 is ok bc559c?

Thanks,

omega12

[zisme]

Can i use BC559C for Q2 because i can´t find MPSA70? What T can i use for Q2 for better amplification?

Thanks, omega12

The BC559C should work fine. Any general purpose PNP transistor with a beta of 40 or more will operate about the same. Q2 just gives power gain to drive the transducer. The output of the 555 is pulses so the transistor is simply turned on and off. It is not really doing any voltage amplification. I used a MPSA70 because I happen to have a few hundred of them.

Have fun,

Mike

[zisme]

Hi,

27 Turns with 0.9 mm wire or 1.0 mm wire??? Q2 is ok bc559c?

Thanks,

omega12

The 20 Ga. wire, I used, is a little over 0.8 mm so I would use the 0.9 mm. Worst case, the outside diameter of the finished coil will be a little larger.

Mike

[Power]

Does anybody have the pcb in physical dimensions?If so I would like to have it.Thank you.

[zisme]

Does anybody have the pcb in physical dimensions?If so I would like to have it.Thank you.

The finished board is 3 x 4 inches.

Mike