One of the best circuit diagrams I have ever experimented with, quite sensitive with very good performance over wide range of frequencies. Thanks a lot man, really appreciate your kind effort.
Thank you so much for sharing so many good and useful designs and tips in your channel. I like the way you present in your videos, which is always short, clear and straight to the point.
Hello, what should I do to make the circuit stronger and able to detect from a greater distance? I have a milliampere meter. Can I use it in this circuit?
Superb explanation on the workings of the wheatstone bridge and jfets. I'm really interested in your RF charge pump configuration, I understand what's it doing functionally but would like to know how you calculated/arrived at the values you used. Any chance you can do a more detailed explantion of it?
The charge pump is a Greinacher voltage doubler. The values chosen reflect the high-Z input of the FET and RC time constants. Here is some info on the circuit: www.electronics-tutorials.ws/blog/voltage-multiplier-circuit.html ua-cam.com/video/IqzA3-bgIIE/v-deo.html
@@0033mer Many many thanks for the links, gonna go through them now and hope that I understand the formulas involved. Your capacitor values are actually in nano farrads or are they pico? Excuse my ignorance ;)
Hello, you did a good job. How is it possible for the second mosfet to work? I do not understand. The signal that should come to the gate leg, which will trigger the mosfet, can only come through 1M resistor. However, I think that after 1M resistance the signal is already connected to ground, it never reaches the gate leg of the second transistor. Bu nedenle, 1M dirençten sonra kablo, ampermetrenin 1k dirençle sıfırlandığı yere bağlanmamalıdır. Is not it?
The first FET detects the RF field and unbalances the bridge for a meter deflection. The second FET makes up the right hand voltage divider. The resistance of the second FET changes when the null pot is adjusted. You could use a resistor in place of the second FET but it would have to be changed to a different value each time the meter is zeroed.
Hi, I know this is off topic but I’d like to know your opinion about this Arduino kit on Amazon amazon.com/dp/B07B7JJQMF/ref=cm_sw_r_cp_api_i_je8RCbGHPXPK2 I’m completely new to this, but I really want to learn how to use them, and since you’re very experienced and based on the price and all the components and sensors that come with it, is it worth buying it or is the price too high?
If you are really serious on learning about microcontrollers and interfacing to other devices the kit has everything you will ever need to keep you busy for a long time. The cost is probably cheaper than if you had to order everything separately with shipping costs and waiting time. You can't put a price on education. Hopefully you do not lose interest quickly and your kit ends up in the corner collecting dust.
One of the best circuit diagrams I have ever experimented with, quite sensitive with very good performance over wide range of frequencies. Thanks a lot man, really appreciate your kind effort.
You're welcome. Thanks for your feedback and sharing.
Thank you so much for sharing so many good and useful designs and tips in your channel. I like the way you present in your videos, which is always short, clear and straight to the point.
Thanks for the feedback. That's what keeps the channel going.
Excellent demonstration, thanks for sharing it with us!
You're welcome!
Keep it up 👏🏼👏🏼, can't wait for the next video
first comment is for me thanks you are improving my knowledge and it helps me in my work.every day I work better best regards for you.
Another excellent tutorial... Thanks
Thanks for the feedback!
nice video
wow Impressive
You have lots of cool electronics tools and meters. Ever think about making a video tour of your electronics lab ?
Here is a pic: www.dropbox.com/s/4xsakafu9hr91j0/Desk.jpg?dl=0
Hello, what should I do to make the circuit stronger and able to detect from a greater distance?
I have a milliampere meter. Can I use it in this circuit?
Superb explanation on the workings of the wheatstone bridge and jfets. I'm really interested in your RF charge pump configuration, I understand what's it doing functionally but would like to know how you calculated/arrived at the values you used. Any chance you can do a more detailed explantion of it?
The charge pump is a Greinacher voltage doubler. The values chosen reflect the high-Z input of the FET and RC time constants. Here is some info on the circuit: www.electronics-tutorials.ws/blog/voltage-multiplier-circuit.html
ua-cam.com/video/IqzA3-bgIIE/v-deo.html
@@0033mer Many many thanks for the links, gonna go through them now and hope that I understand the formulas involved. Your capacitor values are actually in nano farrads or are they pico? Excuse my ignorance ;)
The value of the capacitors are in nano farads "nf"
Another question, what kind of capacitors you used (the blue ones)?
They look like film capacitors.
The capacitors are multilayer ceramic. They work well in RF applications.
Hello, you did a good job. How is it possible for the second mosfet to work? I do not understand. The signal that should come to the gate leg, which will trigger the mosfet, can only come through 1M resistor. However, I think that after 1M resistance the signal is already connected to ground, it never reaches the gate leg of the second transistor.
Bu nedenle, 1M dirençten sonra kablo, ampermetrenin 1k dirençle sıfırlandığı yere bağlanmamalıdır.
Is not it?
The first FET detects the RF field and unbalances the bridge for a meter deflection. The second FET makes up the right hand voltage divider. The resistance of the second FET changes when the null pot is adjusted. You could use a resistor in place of the second FET but it would have to be changed to a different value each time the meter is zeroed.
@@0033mer OK. I just got it now. Thank you for the answer.
Am I the only one seeing a differential amplifier with an offset trimmer?
Alternative for jfet ?
You can also build one using a wide band RF amplifier:
ua-cam.com/video/t_RtPClt_Pc/v-deo.html
Hi, I know this is off topic but I’d like to know your opinion about this Arduino kit on Amazon amazon.com/dp/B07B7JJQMF/ref=cm_sw_r_cp_api_i_je8RCbGHPXPK2
I’m completely new to this, but I really want to learn how to use them, and since you’re very experienced and based on the price and all the components and sensors that come with it, is it worth buying it or is the price too high?
If you are really serious on learning about microcontrollers and interfacing to other devices the kit has everything you will ever need to keep you busy for a long time. The cost is probably cheaper than if you had to order everything separately with shipping costs and waiting time. You can't put a price on education. Hopefully you do not lose interest quickly and your kit ends up in the corner collecting dust.
0033mer Thanks for answering!
I’m really serious on learning about micro controllers. I’m actually an engineering student.
That's great that you have your goals setup and know want you want to do.
@@0033mer
You are right. My kit is dusty and thrown into a corner. :)