QUASAR AVR SMD version build

[horbei]

The could only get hot if they are soldered in wrong direktion.

[Artyom]

Hi! Do not waste time and money on the construction of this device. Much better device FORTUNE 2M. Here all the information - http://alltech.at.ua/forum/3-135-1

[ripsdevala]

Im stuck with LM2941 can find anyhere, i read that i can use 7805, anyone know how to use 3 pin to 5 pin adjustable Lm2941? I plan to use 12v battery

[6666]

Im stuck with LM2941 can find anyhere, i read that i can use 7805, anyone know how to use 3 pin to 5 pin adjustable Lm2941? I plan to use 12v battery
[ATTACH]39904[/ATTACH]

I can see lots on ebay.

[ripsdevala]

Too long with delivery, 1 month, i think i should make desAlex board instead...

What if i use only input ground and output 7805, is that okay?, its will have +5v, right???

[6666]

A 7805 will give 5 volts out as long as you wire it correctly, but it needs about 7 volts input for proper regulation, and the legs need to be bypassed so it does not oscillate Do you have a schematic to see what voltage you would have on the input ?

[ripsdevala]

I only have original schematic, please take a look...

[reptooyep]

[ripsdevala]

Thanks for the hint repto, i will work it now.

add 100n both in and out, and change c22 to elco

[reptooyep]

On the TX circuit, i put 1kohm (like on shematic) parallel to the 1n4148 diodes that control the gates of the hexfet.
Those resistors do not appear on quasar_tiny layout.
Maybe i should take them out and see what appens ?
What are they used for ?

[reptooyep]

Without resistors, the hexfet is not driven and the tx on coil is null.
With the resistors, the irf7105 and the two diodes becomes very hot and the supply fail (too much current).
On the tiny version, they are no such resistors. I realy don't understaand .
I have a nice TX0 signal from mcu and the wiring is good

[star]

quasar arm

[reptooyep]

Your detector looks very nice but the thread deals with QUASAR AVR, not ARM version.
But if you can help me to resolve my probles, i'll appreciate a lot.

[horbei]

@reptooyep,
i dont nothing about a tiny version, i have only the schematic from the original Quasar AVR. You wrote that the diodes gets hot, I think you talking about the MUR diodes on the output of the IRF.
Are you shure that the IRF and the diodes are ok? Whithout a coil there is no way for current to flow through the diodes. Is it possible that a diode is build in with a wrong direction (Anode<>Katode)?

[Andi68]

The Gate Resistors are much too high, the Fet can't switch like it should, try 27 Ohm and look at D4
D4 must the same way as D3
But maybe, i am wrong...