My Pulse Oscillation detector project.

[Waikiki_Sweep]

As you can see IRL630 can drive several Amperes (ID) with less then 5 Volts on gate (Vgs). It is not so easy to find a replacement.

[Waikiki_Sweep]

IRL630

L = Logic level gate voltages. With "IRL" MOSFETs you can drive it straight from the microprocessor.
For other MOSFETs you will need to add to schematic MOSFET driver IC or transistor (transistors).

[bernte_one]

hello
i search for some replacements of IRL630
which is the best one?

	Polarity	Struct	Pd	Uds		Ugs	Id	Tj	Fr	Cd	Rds		Caps
1.	2SK1221	N	MOSFET	80	250		30	10	150			0.4		TO220AB
2.	2SK1761	N	MOSFET	75	250			12				0.23		TO220AB
3.	2SK2841	N	MOSFET	80	400			10						TO220AB
4.	2SK2866	N	MOSFET	125	600			10						TO220AB
5.	2SK900	N	MOSFET	80	250		20	12	150		1800	0.3		TO220AB
6.	AUIRFB4127	N	MOSFET	375	200		20	76				0.02		TO220AB
7.	AUIRFB4227	N	MOSFET	190	200			65				0.026		TO220AB
8.	AUIRFB4332	N	MOSFET	390	250		30	60				0.033		TO220AB
9.	AUIRFB4620	N	MOSFET	144	200		20	25				0.0725		TO220AB
10.	HIRF630	N	MOSFET	74	200		30	9	150	28	240	0.4		TO220AB
11.	IRF630N	N	MOSFET	82	200		20	9.5				0.3		TO220AB
12.	IRF640N	N	MOSFET	150	200		20	18				0.15		TO220AB
13.	IRF644	N	MOSFET	125	250		10	14	150			0.28		TO220AB
14.	IRFB23N20D	N	MOSFET	170	200		30	24				0.1		TO220AB
15.	IRFB260N	N	MOSFET	380	200		20	56				0.04		TO220AB
16.	IRFB31N20D	N	MOSFET	200	200		30	31				0.082		TO220AB
17.	IRFB38N20D	N	MOSFET	320	200		30	44				0.054		TO220AB
18.	IRFB4020	N	MOSFET	100	200		20	18				0.1		TO220AB
19.	IRFB4127	N	MOSFET	375	200		20	76				0.02		TO220AB
20.	IRFB4227	N	MOSFET	190	200		30	65				0.026		TO220AB
21.	IRFB4229	N	MOSFET	330	250		30	46				0.046		TO220AB
22.	IRFB4233	N	MOSFET	370	230		30	56				0.037		TO220AB
23.	IRFB42N20D	N	MOSFET	300	200		30	42.6				0.055		TO220AB
24.	IRFB4332	N	MOSFET	390	250		30	60				0.033		TO220AB
25.	IRFB4620	N	MOSFET	144	200		20	25				0.0725		TO220AB
26.	IRFB5620	N	MOSFET	144	200		20	25				0.0725		TO220AB
27.	IRL630	N	MOSFET	74	200		4.5	9.0	150			0.4		TO220AB
28.	IRL640	N	MOSFET	125	200		4.5	17	150			0.18		TO220AB
29.	KF13N50P	N	MOSFET	208	500		30	13	150	45	210	0.35		TO220AB
30.	KF9N25P	N	MOSFET	83	250		30	9	150	25	96	0.31		TO220AB
31.	KHB019N20P1	N	MOSFET	140	200		30	19	150	33	80	0.14		TO220AB
32.	KHB9D5N20P	N	MOSFET	87	200		30	9.5	150	62	96	0.345		TO220AB
33.	PHP20NQ20T	N	MOSFET	150	200			20				0.13		TO220AB
34.	PHP33NQ20T	N	MOSFET	230	200			32.7				0.077		TO220AB
35.	PSMN057-200P	N	MOSFET	250	200			39				0.057		TO220AB
36.	PSMN070-200P	N	MOSFET	250	200			35				0.07		TO220AB
37.	TK13E25D	N	MOSFET	102	250			13				0.25		SC46/TO220AB

Über 37 Ergebnisse

[6666]

Hi Teemo
I had a bit of success and good start to your project
output from pin 2, programmed with Pickit3 and MPLAB IDE 8.76

[TekJosec]

I am currently working at it, to add this feature. Current plan is to make some kind of dual tone sound, so that Ferro NonFerro will make different sounds. I want it to sound something like old times PC speaker music. The information to distinguish is already there, just need to program new sound system.

Struggling with sound algorithm. I guess I will try to make dual tone sound by switching periodically between audio frequencies. Keep one frequency constant, alter other frequency depending on target.

Any ideas welcome! If anyone knows a good page about how pc speaker sound was generated for old games, please post link here!

And why not upgrade the project to another PIC and put a LCD display , headphones output and many other things...
I could help!! my problem is the assembly language, i only program mplab on C language.

Seems a very nice project and waiting for parts to test. About the range of the detector it must be worked (find the better coil project), the entire structure construction (wood, PVC).

[Tec]

Hi,

I am interested in this. I am working on a similar design.

It has good FE discrimination.

There is frequency shift due to a metal target.
I believe this is no different to the frequency shift in a PI pulse, or the frequency (not phase) shift in a 'Induction Balance' detector.

All these technologies do the same thing to a target: Present a changing magnetic field.

The good thing about a free-running oscillator like this is that the tiny shift in each cycle adds-up (compounds) over time, so if you measure over say 1000 pulses, you get a decent measurable change.

Another excellent thing is that power is not wasted in a resistor, it is re-used (i.e resonating)

I believe this style of detector can be more sensitive than any other technology.


I think:
To decrease the sensitivity to high resistance targets (wet sand and ferrite) : decrease the frequency.

[6666]

But I guess I must compile a table of coil inductance, resistance and C1 values.

Anytime soon ?

[BC547]

Hi Teemo,
I really like your design! and I agree with Dave's earlier reply:
It has much potential - especially in the way the change in frequency is an indication on the kind of metal.

To generate tones, you just need to toggle an output pin in the right frequency, as you probably know already.
Have a look at the function 'sound()' here: http://users.telenet.be/willaert/MD/...ckini_16F616.c

Best regards,
- Bernard

[satdaveuk]

Hello everybody.

I got feedback from Andy who has built the project from my website.
He has made the video about testing it.
With his permission I share the link for the video :http://xyolater.bplaced.de/?Videos:Metalldetektor

Best regards,
Teemo

Hi Teemo
That video you posted here from Andy doesn't do your design any justice at all, your better off without it on here.
It starts off ok but within seconds of it starting he has put music on it while dancing around with targets good as touching the coils , How redickulas can anyone get, there's me trying to listen to the response signals from his different targets and its drowned with music.
Also his build didn't seem to be much good far as range, I get better depth out of my £6.99 stud finder.
If you want good advise I would delete that video simply because anybody who had been considering building your design like myself, after seeing that they may well not bother and move on too something else because it portrays to be nothing special, maybe its not, but if it is you want and need as much interest as possible from the tech guys to help further develop it.
I am not having a go at you personally because I respect people like you that have a go with different designs off there own head and also do realize the time and hard work involved, Its just I don't want your project to fall flat on its *** like so many others have.
Matter of interest what sort of depths are you actually getting to-date on this project? I was quite impressed how Apberge has progressed with the pinpoint coil, looks like a manufactured coil very professional.
Last night made another Barrcuda board for further experiments on that design and was going to also quickly make a board for your design but held back to see what Apbergs Sprint lay files look like because I prefer working from lay files there easy altered for experiments if we feel the need.
Anyway keep up the hard work, you got some good clever guys here to help you along the way, all the best

Regards

[Teemo]

Hi. It is nice project. Not recommended connecting to computer to directly. Better way, if you have using an opto-coupler.
Best regards

Rumcajs

Hello!
Yes I know it is generally better to use optocoupler to be safe. So everybody, using direct connection, or any connection to computer only at your own risk!
Anyway I continue to use direct connection myself because of its extreme simplicity, and also it works perfect (as long as circuit is powered by batteries as it normally should be, so no risk of ground loops).

[Rumcajs]

Hi Teemo,

what do you thinh from auto transformer?

http://www.transtutors.com/Uploadfile/CMS_Images/21190_Auto-Transformer.JPG

The LOAD side (see linked pic.) is FET-side, and V1-side is the tank capacitor side, for example 47nf/1kV or serial 4x220nF/250V (the result is approx 55nF), and paralel an bigger damping resistor.

[Rumcajs]

Hi. It is nice project. Not recommended connecting to computer to directly. Better way, if you have using an opto-coupler.
Best regards

Rumcajs

[Xtrem]

sound

https://en.wikipedia.org/wiki/General_Instrument_AY-3-8910

[Davor]

You could go for a pulse-counting FM/PM detector which is very resilient to amplitude change, but discrimination will be influenced with coil loading, as in essence it will perform as an off-resonance detector with FM/PM sensing.
Pulse-counting detector? Just count zero crossings over a constant period.

[Teemo]

Hi Teemo. Congratulations on this inventive design.

On your web site you say: "There is no discrimination between metals."

But this is basicaly intermitent BFO, and BFOs are able to distinguish between Ferro and NonFerro (by changin oscillator frequency Up or Down). This is very interesting potential of your design in comparison to equal PI uC solutions. Why you would not take this very interesting advantage / potential of your design?

Expecting your next firmware with Ferro NonFerro distinguish capability.

I am currently working at it, to add this feature. Current plan is to make some kind of dual tone sound, so that Ferro NonFerro will make different sounds. I want it to sound something like old times PC speaker music. The information to distinguish is already there, just need to program new sound system.

Struggling with sound algorithm. I guess I will try to make dual tone sound by switching periodically between audio frequencies. Keep one frequency constant, alter other frequency depending on target.

Any ideas welcome! If anyone knows a good page about how pc speaker sound was generated for old games, please post link here!