wrist strap tester

[ericgibbs]

hi..
i'm really interested in that.
And i have checked the given ckt. that was really nice.but that is not suitable to use in an industry.

thnx

hi tnuflora,
Look at the attached pdf.
The design has been built and checked OK, using loop resistances of 330K thru 1M0 and a short circuit loop.

You will understand, as I will not be the person building and using this unit I will not be held responsible
for any damage or injury that may result from using this design.

EDIT: added 1M0 hysteresis resistor.

 

[sumesh75]

The why not just BUY ONE!

Spend some money.

JimB

ΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘΘps..
I didn't know that
thanks for your kind information........

 

[tnuflora]

wrist strap

hi tnuflora,
Look at the attached pdf.
The design has been built and checked OK, using loop resistances of 330K thru 1M0 and a short circuit loop.

You will understand, as I will not be the person building and using this unit I will not be held responsible
for any damage or injury that may result from using this design.

thnx..................

 

[tnuflora]

thnx..................

hi eric,


i was working with the circuit that u have given.
In that safe operation is working fine.but
fault condition is not at all indicating.
can u give some more details about the working of the circuit ?

 

[ericgibbs]

hi eric,


i was working with the circuit that u have given.
In that safe operation is working fine.but
fault condition is not at all indicating.
can u give some more details about the working of the circuit ?

hi,
Pleased to hear the tester is OK.

Regarding the Fault, this LED will light if the high value resistor has been removed from the strap and a link used to replace the resistor.

In other words its a strap with no series protection resistor, which is UNSAFE.

I have seen instances where the wire with the resistor has broken away from the wrist strap, due daily use, and the user has connected just a piece of wire to the strap, which is a bad idea.

OK.

 

[tnuflora]

strap

hi,
Pleased to hear the tester is OK.

Regarding the Fault, this LED will light if the high value resistor has been removed from the strap and a link used to replace the resistor.

In other words its a strap with no series protection resistor, which is UNSAFE.

I have seen instances where the wire with the resistor has broken away from the wrist strap, due daily use, and the user has connected just a piece of wire to the strap, which is a bad idea.

OK.

hi,
sorry, i mean ,even if i removed the high value resistor then also the fault LED is not glowing.

 

[ericgibbs]

hi,
sorry, i mean ,even if i removed the high value resistor then also the fault LED is not glowing.

hi,
Its just a 1K0 resistor on series with a Red LED.
The 1K0 goes to the +V of the battery and the cathode of the LED goes to -V of the battery.

I would suggest you check the 1K/LED and the wiring.

Are you completing the circuit by touching the 'test probe' to the earthing stud of the wrist strap.?

 

[tnuflora]

streap

hi,

Are you completing the circuit by touching the 'test probe' to the earthing stud of the wrist strap.?

hi,

i just removed the high value resistor.

 

[ericgibbs]

hi,

i just removed the high value resistor.

Did you replace the removed resistor with a wire link.?

The purpose of the Fault LED is to check a wrist earthing strap thats made without the high value resistor..

On this attachment I have marked the connections points more clearly.

 

[tnuflora]

Did you replace the removed resistor with a wire link.?

The purpose of the Fault LED is to check a wrist earthing strap thats made without the high value resistor..

On this attachment I have marked the connections points more clearly.

hi,

there i made a mistake. i've not connected the wire link.

 

[tnuflora]

Did you replace the removed resistor with a wire link.?

The purpose of the Fault LED is to check a wrist earthing strap thats made without the high value resistor..

On this attachment I have marked the connections points more clearly.

hi,

i've a question...if the strap is made with a high value resistor & for some reasons it fails,how the circuit will respond to it?

i mean , the connection to the gnd will be disconnected & it will be an open ckt. w'll the red LED glows ?.

 

[ericgibbs]

hi,

i've a question...if the strap is made with a high value resistor & for some reasons it fails,how the circuit will respond to it?

i mean , the connection to the gnd will be disconnected & it will be an open ckt. w'll the red LED glows ?.

If the resistor is too high a value or open circuit the Green 'PASS' led will not light.

 

[tnuflora]

strap

If the resistor is too high a value or open circuit the Green 'PASS' led will not light.

hi..

i need to know abt the red LED at that condition.

 

[ericgibbs]

hi..

i need to know abt the red LED at that condition.

I have already answered that question.

hi,
Pleased to hear the tester is OK.

Regarding the Fault, this LED will light if the high value resistor has been removed from the strap and a link used to replace the resistor.

In other words its a strap with no series protection resistor, which is UNSAFE.

I have seen instances where the wire with the resistor has broken away from the wrist strap, due daily use, and the user has connected just a piece of wire to the strap, which is a bad idea.

OK.