automax precision pinpointer

[kt315]

was traced. joy.

[Geo]

was traced. joy.

Hi KT315. Good work. Please can you tell me about swich SA1. Is it a 3 position or there is another swich for on-off?
Regards

[detectoman]

hi kt315 what features or advantages have these cachibache? is new? what is the power of penetration, what deep , is one pi or is other? thanks excusme for my english
regards to you kt315 and geo
detectoman

[kt315]

you may see Automax Precision v4 here
http://www.kellycodetectors.com/vibr...pinpointer.htm
what differences are between V2 and V4 I do not aware.

[Geo]

is one pi or is other?
detectoman

It is a Bfo type but i can not see the retroaction on the oscillator.

[Kitsune]

It is a Bfo type but i can not see the retroaction on the oscillator.

Nope, not a BFO. It's the same principle as used in CS209 proximity detector chip - measuring the Q of the LC tank (or the losses due to eddy currents in conductive objects nearby - just different wording). It senses change not in frequency but amplitude of oscillations.

[kt315]

if to be a due its principle is a failure of oscillations, or skip out of oscillations on a metal. in normal mode w/out metal proximity it generates the oscillations on 100 kHz.
can anyone share FUNKAMATEUR 1980/8 magazine with the article, in German?

[kt315]

in additional. enjoy.

http://www.md4u.ru/pdf/ru01_simplemd.pdf http://www.md4u.ru/obmen/underwater_pp.zip

[migusch]

Some questions...

Thank you kt315 for providing this interesting pinpointer-schematic.
It seems to be exactly what I was looking for a long time now.
But for an electronic beginner like me, there are still some remaining questions:

VR1 ??? which value? (should be very easy to measure with DMM!!)
C2 ??? -> probably between 1pF and 100nF, because these are common values in size code 0603 (1,6*0,8mm)) (I have to go the trial-and-error-way, I guess...)
Z1 ??? does its value correspond to the "+4V4" written not far from the z-diode?? So is it probably a 4V3-type?? [as common values are 2V4 2V7 3V0 3V3 3V6 3V9 4V3 4V7 5V1 5V6 6V2 6V8 8V2 7V5 9V1...]
Z2 ? does it correspond to the voltage of the vibro-motor used, for example: 5V1 for 5V-Motor???? Is that correct?
D1,2,4 ??? 1N4148 should probably do it?

L1,L2 ??? abuot how many turns each? (Do both coils have the same amount of turns?) Which diameter/awg/swg??? Estimated Diameter and length of ferrit-core??

The Buzzer: is it just a solely Piezo-Membrane or is it a complete piezo-buzzer with driver-circuit inside (frequence-generator)? The given polarity makes me think it is most probably the second of both. Am i right?

As you can see from my questions I am not that good in reading electronic schemes and calculating the missing values on my own. Unfortunately I rely on as much given facts as possible when I want to have a serious chance to rebuild a circuit like this one.
A photo of the other side of the PCB and especially the coil would have been a little help for me.
Due to language-problems the cyrillic description of the upper schematic doesn´t help me as well (most probably it is a similar coil-combination!!?...)

Did anyone rebuild this circuit so far?
Does anyone know a similar pinpointer-circuit with common middle-european / american electronic parts where the values are all given (including the coil...)?
Thank you for your help,
migusch

[Esteban]

This is Funkamateur January 1980, re-published in a Romanian magazine.

[technos]

Here is the google translation for Estaban's funky "FUNKAMATEUR";

SEARCH FOR METALS

Aparatu Seveste device to despistarea water pipes, electric cables or other objects from walls.

Transistor T1 forms a floor to about 100 kHz oscillator transistor T2 signal takes, it redreseaza and control transistors T3 and T4 which leds to a collector.

When T1 oscillates enuluminaza leds, and when not oscillating T1 - situation when the coil L1 is close to a metal - leds starts to shine. The sensitivity of the device is adjusted in potentiometrele R5, R6, R7

Transistors T5 and T6 form unstabilizator voltage. They can replace a zener of 4 V.

Transistors T1, T2, T3, T4 can replace the BF 215.

Coils are built on a bar away from the antennas of the radio. L1 has 120 turns and L2 is 45 turns CuEm 0.3.

<<FUNKAMATEUR>>, 1 / 1980

Divining the romanian spanglish I come up with the following - maybe somebody can correct or improve upon it.

SEARCH FOR METALS

A small device to to detect water pipes, electric cables or other objects in walls.

Transistor T1 forms a floor to about 100 kHz oscillator transmitted to T2, and sent to control transistors T3 and T4 which control the LED at the collector.

When T1 oscillates the LED is off, and when not oscillating T1 - a situation when the coil L1 is close to a metal - LED starts to shine. The sensitivity of the device is adjusted by potentiometers R5, R6, R7

Transistors T5 and T6 regulate voltage. They can be replaced by a 4V zener.

Transistors T1, T2, T3, T4 can be replaced by the BF215.

Coils are built on a ferrite rod from the antenna of a radio. L1 has 120 turns and L2 is 45 turns 0.3mm diameter magnet wire.


Cute circuit

[technos]

I didn't get a chance to edit when I just discovered this tidbit;
Funkamateur == Radio Amateur == ham radio

[NELLTORNADO]

Thank you kt315 for providing this interesting pinpointer-schematic.
It seems to be exactly what I was looking for a long time now.
But for an electronic beginner like me, there are still some remaining questions:

VR1 ??? which value? (should be very easy to measure with DMM!!)
C2 ??? -> probably between 1pF and 100nF, because these are common values in size code 0603 (1,6*0,8mm)) (I have to go the trial-and-error-way, I guess...)
Z1 ??? does its value correspond to the "+4V4" written not far from the z-diode?? So is it probably a 4V3-type?? [as common values are 2V4 2V7 3V0 3V3 3V6 3V9 4V3 4V7 5V1 5V6 6V2 6V8 8V2 7V5 9V1...]
Z2 ? does it correspond to the voltage of the vibro-motor used, for example: 5V1 for 5V-Motor???? Is that correct?
D1,2,4 ??? 1N4148 should probably do it?

L1,L2 ??? abuot how many turns each? (Do both coils have the same amount of turns?) Which diameter/awg/swg??? Estimated Diameter and length of ferrit-core??

The Buzzer: is it just a solely Piezo-Membrane or is it a complete piezo-buzzer with driver-circuit inside (frequence-generator)? The given polarity makes me think it is most probably the second of both. Am i right?

As you can see from my questions I am not that good in reading electronic schemes and calculating the missing values on my own. Unfortunately I rely on as much given facts as possible when I want to have a serious chance to rebuild a circuit like this one.
A photo of the other side of the PCB and especially the coil would have been a little help for me.
Due to language-problems the cyrillic description of the upper schematic doesn´t help me as well (most probably it is a similar coil-combination!!?...)

Did anyone rebuild this circuit so far?
Does anyone know a similar pinpointer-circuit with common middle-european / american electronic parts where the values are all given (including the coil...)?
Thank you for your help,
migusch

Hey you do this ma shin )


VR1 ??? which value? (should be very easy to measure with DMM!!)
C2 ??? -> probably between 1pF and 100nF, because these are common values in size code 0603 (1,6*0,8mm)) (I have to go the trial-and-error-way, I guess...)
Z1 ??? does its value correspond to the "+4V4" written not far from the z-diode?? So is it probably a 4V3-type?? [as common values are 2V4 2V7 3V0 3V3 3V6 3V9 4V3 4V7 5V1 5V6 6V2 6V8 8V2 7V5 9V1...]
Z2 ? does it correspond to the voltage of the vibro-motor used, for example: 5V1 for 5V-Motor???? Is that correct?
D1,2,4 ??? 1N4148 should probably do it?

L1,L2 ??? abuot how many turns each? (Do both coils have the same amount of turns?) Which diameter/awg/swg??? Estimated Diameter and length of ferrit-core??
............this all correct?

[kt315]

much strange people see on schematics and do not see NOTHING!
this world seems is filling up by the lunatics!!!

[kt315]

Metal detector for project or pinpointer

http://cgi.ebay.com/Metal-detector-p...item4cf21ca34b

On off switch, sensitivity control. Uses 9 volt battery. Red led lights when metal detected. piezo buzzer can be used accross the led. I tried one from radio shack( 1.5 - 3 volt ). (Piezo buzzer not included). USA shipping only.