I have an ideea 5534

[baluba]

Hi, i have seen that there is an OP AMP 5534 which is a low noise. Could we use it to improve the MPP performance?

I have read on different forums that 5534 is better in terms of noise compared to 071. I might be wrong...

[Silver Dollar]

Well if your using this schematic then it uses
the 5532 which is a dual opamp based on the 5534...

The first opamp sets the noise floor later ones do not have to be as good.

[Jose]

I did not build the Minipulse, but usually to improve performance, could increase the TX pulse width of 100 ns or more, also remove the 3.3 ohm resistor in series with the coil and place a jumper in place.
The current design of Minipulse, seems to cater to the detection of gold and battery performance, which is not necessary as pulse width.
Besides the limitation of the current in the coil, improves the delay time.
But for relics in general, could attempt the above.
It's just my thoughts.
Jose

[baluba]

I will try to remove the 3,3 ohm resistor. I hope not to burn the transistor irf740, since my coil is 0,6 ohms and 12V/0,6ohm is 20 Amp, the transistor is rated for 10 amp continuous, and 40amp pulsed but...

[Jose]

Calculation for Miscel program indicates a maximum current of 3.2 Amper
Facts:
Tension; 12 volts
inductor; 300 mH
Estimated total resistance; 1.2 ohms (Coil + IRF740 + Cable)
TX; 100 microseconds
Jose
[ATTACH] 31918 [/ ATTACH]

[Qiaozhi]

Calculation for Miscel program indicates a maximum current of 3.2 Amper
Facts:
Tension; 12 volts
inductor; 300 mH
Estimated total resistance; 1.2 ohms (Coil + IRF740 + Cable)
TX; 100 microseconds
Jose

The coil should be 300uH, not 300mH.

[baluba]

i did not taken into account the transistor resistance... my bad