Making Chance md stronger

[Mrbeen]

Hi to every body, ;
I would like to make my chance metal detector stronger, l mean to go deeper so
I used 18 volt electricity instead of 12 volt.
it works for one second and then it stop working,
the ic 7662 breaks down ,, I try few times same ic fails.
I don't understand what is the reason for this problem?
is it to do with higher amper?can you help?please

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[Carl-NC]

Might be a fake chip, perhaps a re-marked 7660. Try taking just the 7662 and connect it to 18V with no load, see what happens.

[Mrbeen]

Hi
yes you are right could be a fake one or low quality copy of chip,
in my country there is more fake chips than original ones.
unfortunatly

[Mrbeen]

I looked more I found capacitor c9 is placed reverse ,
could it reason why ic 7662 burning??
some body said the design of chance cicuit md has got
problem .I don't know....

[Carl-NC]

I looked more I found capacitor c9 is placed reverse ,
could it reason why ic 7662 burning??

I would not think so.

[Mrbeen]

Hi
I fixed capacitor c9 ,test it .same thing happened .ic 7660 burn out .
now I am going to change ice no 5534 .
Will see if problem gets solve.!
thanks for your attention

[Mrbeen]

Hi I remember now I used voltage converter ,probably that caused damage to the device
by sending higher voltage......
probably the main ice ice damaged too.....

[Mrbeen]

Hi my dear friends
Eventually I got it working normal then I put ice 7662 in it and
connect 18 volt current to it by using two battery and a regulator,
now device is working kind of fine but it is not much strong ,
is there any thing else I should do???.!!!...
thanks for help

[Detectorist#1]

Hi Mrbeen,
7662 as the datasheet, have to work from power supply voltage 1.5 to 15volts. Don't be surprised from burning when 18 Volts are used.

[Detectorist#1]

In my practice, I try to use 7660 (max 10Volts as datasheet) with 12V power - the result is -very soon damage!

[Detectorist#1]

You try to make Chance PI MD stronger in what - in the deep or in the sensitivity for smaller targets? According my opinion, this design is not capable for increasing the sensitivity for smaller targets - very slow and low resolution ADC is used. For more deepness have possibility with bigger size of the coil (only for bigger size targets).

[nejdet]

Hello, I used a 7660 in one of my projects purchased from China and guess what - 15 chips were defective! Draw your own conclusions about what is being sold there! They burned out on a test board at 8 volts!

[Detectorist#1]

Fake chips are big problem. Only solution is to make 100% incoming control unfortunately. This is possible for large companies, but for hobbyists no simple solution.

[Detectorist#1]

Approximately 10 years ago, I used RS485 chips in one of my projects for computer's net. The chip SN75176A (capable of support up to 32 nodes) was labeled as LTC1487 (capable of support up to 256 nodes). Current consumption of the first is 35mA and for the second is 0.12mA. As the result - The set of computers worked very unstable when the number of nodes began to be more than 32.

[SWAMPFOX]

It's simple you are exceeding the proper operating voltage. As long as you keep putting too much voltage ⚡️ you are going to keep destroying components.