Development box

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I'm constructing for me a stable unity consisting of:

Dual power supply
pll frequency generator circuit with 1/1000 1/100 and 1/10 divisions including switches for changing capacitor 1-10-100nf thereto consequently the bandwidth...
variable frequency with variable 0-100% pulse width generator (gate frequency)
Feedback pulse indicator circuit
resonant scanning circuit 0,722Hz 1-11v triangle
auto-manual frequency tuning
testpoints easy to use

three outputs
bipolar transistor pulsed, mosfet pulsed and
there is going to be my add that is a full wave bridge output that  works even using the gate

I had an idea... as i can construct one i can construct 5

I'm willing to sell it if you are interested in having such a box for testing. I can construct one for you for 500$ shipping non included

It will take some time to make it probably 1 week or less... 

I'm going to make only 5!  if requested... all hand made... tested...

The only connections you will got to do is to the wall plug, to a dc source, and to the whatever you want to test. easy to go so you just need to work on coils...

this unity will put some juice into the coils...

one great thing is the ability to use different outputs at same time at same frequency...

It may be included a dc conversion straight from the wall with current limited by capacitance...

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That a great offer, Sebosfato
I mean, really great!

Steve

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Hope it helps... will help me too 

I want to buy some more wire and cores and an agilent desktop multimeter...

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I think the best thing is that getting one like this you don't wast time building and rebuilding stuff... until get one that works... i already done that for 6 years... so i'm offering to few who wants to test like grew up people my experience and some of my time to build this specialized units... is not a black box because now there are some instructions to what can be done with it... and how each part of it works... so if you get one you can tweek your values with easy if required...

This Is something that you could construct by yourself with some time and effort but as i'm willing to do it for you for such low price i hope it can save you some work and money, waste in components and precious time...   

There will be also easy access to test points for vco, output pulses, feedback, gate, and scan circuit...

some applications for example:

determine the capacitance of the water cell by finding the resonance frequency...
 
combining frequencies... detecting, following...


500$ includes all components, diagrams... and instructions...

inside you find

power supply:
1 110-220 switch
2 transformers
3 rectifiers
big current limit capacitor
5 big capacitors
4 voltage regulators
10 smaller capacitors
3 heat dissipators

PLL - feedback
4 way switch (panel) (freq range)
2 variable resistors (panel) (frequency off set and manual scanning)
1 two way switch (panel) auto-manual scanning
3 cd4017
1 lm318
1 cd4046
1 ir4427
1 cd4001
1 cd4016
3 2n3904
3 leds (panel)
resistors
capacitors


Gate - resonant scan
2 Ne555
2 lm741
2 variable resistors (panel) (pulse width and frequency)
resistors
capacitors
4 way switch (panel) (freq range)


Full wave H bridge output:

2 optoisolators
1 cd4001
2 ir4427
resistors
2 irf640
2 irf940
4 diodes
heat dissipator

mosfet output
 
resistor
capacitor
diodes
power mosfet
heat dissipator


using less components is harder to get problems in the circuit... another feature is that i'm using only components that are currently available and will still be for a long time...

for example while stan gate circuit uses 6 ICS i use only 2 and 4 capacitors... it makes the same exact thing much cheaper simpler, compacted, and problem avoider... here at sao paulo i could not find the 74ls122 for example... nor the nte918... so i got around... 



....

I'm finishing the one i'm building for me... all parts of the circuit worked at first run... this is very nice.


So all this components sums to more than 150dollars here... now include 1 week or so of hard work of my time, effort and art... 

all hand made with care!

500$ is too cheap... and i'm not willing to do nothing for less than this...

If you want only the board with no components soldered i could do one for 150$ and for 300$ i could include all components in a kit and send to you with instructions... but is not what i would like to do... i would like to send to you something working and tested.

I repeat is all hand made... I use a kind of pencil with which i make the circuit drawing and than i can corrode the copper remained with a kind of acid... than i drill the holes and the board is done... this kit costed me around 50$

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I forgot to say that on this gate circuit used, the frequency is totally independent of the duty cycle, so both can be adjusted independently without affecting each other... It goes from 0-100% perfectly... The duty cycle is aways proportional to the frequency and maintain perfect proportionality.. Changing the duty cycle the frequency remain constant, and vice-versa.
 
I just wanted to let clear that this gate circuit makes exactly what stans gate frequency circuit does... its only different than meyer circuit in the way the frequency range and pulse width are regulated, but it does exactly the same thing with same affordability and range and all... in my view better because its simpler...

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I developed a new idea that would allow to detect resonance easier... I'm going to add this option to the box...

Its going to be able now to ignore completely the signal frequency and than discriminate a resonant condition only by its signal level.  I guess stan system should already done that but splitting tasks makes it lot easier... 
this way when the scanning circuit sends frequency close to resonance the signal is allowed to go into lock in...
basically this is major improvement when dealing with sensitive systems. It would avoid false lock in outside of the resonant range which causes locked out of resonant condition..an since the lock in determine the scanning action, it would help keep scanning more effective.

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The problem is that if it locks in to a signal that is not at or close to resonance the pll will go toward the lowest frequency it can... if i recall correct..