Bulgarian 'PULSE STAR' (... close to Legendary one)

[mesy64]

Hello Messyna ,
In your schematic of 555 ... i did not see 2 diodes check ... you must have 2 diodes 4148 , ok
1) First do not solder the IRF 740 in your board....
2) check very well your 555 circuit (2 diodes) and check the output you must have a good pulse and adjust this pulse at the frequency of 120 ...150 Hz .... when you have the frequency adjust the wide of this pulse to 200 uS.... after do not touch more this trimmers o pot
3) now you can solder your IRF 740 it will not burn, ok

It is the first and more important thing this part ,when you will have your 740 running it will be more easy to check the next part ,
Alexis.

dear Alexismex and georgi.g.zhelev
I plan to outline Electronic oscillator you have modified
555 output frequency 120 Hz to 280 Hz was
But when the coil connected to the machine I was hot and extremely irf740 burn and r8
My part to separate oscillator and built on a separate range but still extremely hot in ifr740 and fuel
I'm really tired. I do not know where my work is difficult
C6 in the amount of the hot and burning 740 to be effective?
Please help me. realy I need your help
With respect
mesyna

[mollax]

dear Alexismex and georgi.g.zhelev
I plan to outline Electronic oscillator you have modified
555 output frequency 120 Hz to 280 Hz was
But when the coil connected to the machine I was hot and extremely irf740 burn and r8
My part to separate oscillator and built on a separate range but still extremely hot in ifr740 and fuel
I'm really tired. I do not know where my work is difficult
C6 in the amount of the hot and burning 740 to be effective?
Please help me. realy I need your help
With respect
mesyna

Check coil and its parallel resistance to heat her irf740

[mesy64]

Check coil and its parallel resistance to heat her irf740

dear mollax coil is 300mh and 1.8ohm.it is resistance whit resistance 270r

[mollax]

dear mollax coil is 300mh and 1.8ohm.it is resistance whit resistance 270r

Is 0.9 ohm coils with 32 laps 0.5 kabolo check coil

[georgi.g.zhelev]

puls star-g

dear Alexismex and georgi.g.zhelev
I plan to outline Electronic oscillator you have modified
555 output frequency 120 Hz to 280 Hz was
But when the coil connected to the machine I was hot and extremely irf740 burn and r8
My part to separate oscillator and built on a separate range but still extremely hot in ifr740 and fuel
I'm really tired. I do not know where my work is difficult
C6 in the amount of the hot and burning 740 to be effective?
Please help me. realy I need your help
With respect
mmesyna, mesyna with how big the letters should you write: 555 pin 3; pulse f = 120hz; pulse width = 150 mikrsekunds !!!!!!!!!!!!! (pulse width determined !!!!!!) pulse power, you reduce it too wide to R2 POWER =150mikrsecunds !!!!!!!!!!!! IRF740 TO put a small radiator.

[Alexismex]

Hello Forum ,
Ok Messyna y Georgi , for me it is Almost the same for the power ( you have a 50 Ma of diference )200 Micro second o 150 Micro second...
for the test fix the RV1 to 120Hz and the trimmer RV2 to 150 Us ...and all is fine
But if you have this design and your 740 is very hot ....you must look is another problem and for me i do not see where???
1) see in 1 do you have really the pulse of 120Hz and 150 uS test with and osciloscope ..ok
2) see in 2 in you solder well this transistor bc 337
3) see in 3 if you solder well this bd140
4) see if you put really a 240 R and not a 24 R or 2R4
IT is very simple design you must have conected bad one transistor ...ok
Check welll and you will have this worK
nice
Alexis.

[Alexismex]

Check well again

[Alexismex]

Hello Georgi,
Today i have checked and adjusted the discrim , sometimes is good sometimes it fail , i use two sheet of metal 10 X10 cm one in copper the another in iron....
please , can you give me the best adjustment for the channel X Ferros : How did you fix with RV5... at 0,, 10... 20 uS o more the window see my drawing and another thing see the photo the pot discrimination you use RV11 o RV5 tell me...you move this potentiometer to adjust the center after you push the Zero ???

Thank you very much Georgi
Alexis.

[georgi.g.zhelev]

PULS STAR-G

Hi,ALEXIS!1. Potentiometer RV3 (DELAY) put in a position of maximum sensitivity and stable operation of the audio channel. (do not touch more)
2.RV5 discrimination> See ostsilograma scheme. (Q6 colector) fixed and not touch more!
3.RV7, RV8> putting U7A (TR3) 0V. more .. do not touch!
4 .. Potetsiometar RV11 >discrimination indicator to zero.
5 .. Push and relax ZERO, RV11 ... indicator of discrimination> 0 <!
UNDER INDICATOR ,POTENCIOMETER RV11! (NO RV5,RV10)

IMPORTANT! BEFORE SETUP, OFF TV!! (ALL TV> OFF)
CHANNEL discrimination is very sensitive! G.L.!

[mesy64]

DEAR georgi.g.zhelev AND Alexismex
Finally, I solve problems I hot transistor.
Electronic oscillator separately building and in stages so that currently have the frequency of 120 Hz and irf740 not hot. Electronic oscillator is true then
Electronic oscillator stage next to the metal detector circuit I work, but added depth of disclosure is too short
Please increase the depth of my disclosing to tips.
I What should I do?
If the basic transistor gate irf740 directly BD140 transistor collector is connected through resistance or 4.7K???? You disclosing this deep impact?
Which is correct?
Please help me
With respect
MESYNA

[georgi.g.zhelev]

ps-g

If the basic transistor gate irf740 directly BD140 transistor collector is connected through resistance or 4.7K???? You disclosing this deep impact?
Which is correct?

4.7k what? a scheme where you see 4.7k? mesyna,shematic is corect,se shematic!

[Alexismex]

hello Georgi ,
Today i check all the circuits , all is fine and working well Thank you for your help to morrow i will reajust like you say the preset ,ok...
Do you experiment with the BD 140 it is necessary this big one , a small transistor work also like the BC 327 ????
See my prototype experimenting boards, it is big one but this way i can check very well all the signals good ...now i can design the board 2 trace.
Have a nice day,
Alexis

[mesy64]

hello dear georgi.g.zhelev
I got size of the output pulse 3 (555)
Its waveform to these three conditions are
i do not know the values for the horizontal and vertical have properly set or not?
Please set me for the best waveform and to determine the main values to the horizontal and vertical guidance.
With respect
mesyna

[georgi.g.zhelev]

PS-G

Hi, mesyna! I see, 5.049 mv ...ok. puls 499.2mks ..no ok. power trimer 150mks!!
f= 1.002Khz , no ok ! trimer freq. 120HZ!!

I have not worked with a virtual ostsilostsop, but nothing complicated.
1. horizontal placed on 50mks ..
2.vertikal ..... 2V.
Se check scheme and other control points ostsilogam governed by three-dimensional. coil has 500 .... 600v, there did not include! will damage the oscilloscope, you must include it in atenyuator (x 10). As I have described above how to set. then include the probe of NE5534 pin 6, there will watch the signal is there a change when there is metal.
G.L!

[georgi.g.zhelev]

PS-G

Hello, ALEXIS! Very good, mikroampermetar supposed to be a zero in the middle,> 0 <. Discriminator Write how it works well? Discrimination sensitivity of the LED is small! A key indicator of discrimination is mikroampermeter!