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How can i add a trigger to this circuit to make it not electrocute the user?

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(*steve*)

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703? I don't see a 703 in that circuit. The general answer is to look up the datasheet.
 

Name...

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Sorry about that, i mean the pin layout for the thyristor with number on 703
 

(*steve*)

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Do you mean your SCR is an ON703?

I can't find an SCR with that part number, sorry.

Can you post a picture of it?

If you know anyone with a universal semiconductor analyzer you could hook it up and it would tell you. (something like this http://www.peakelec.co.uk/acatalog/jz_dca55.html)
 

CDRIVE

Hauling 10' pipe on a Trek Shift3
May 8, 2012
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Since your electronics interests seem to span beyond this single project you might be interested in owning one of these...
http://www.ebay.com/sch/i.html?_fro...3.TR0.TRC0.H0.XGM328.TRS0&_nkw=GM328&_sacat=0

Most, if not all of the items you see in this listing are similar to the model that Steve has but with more robust displays plus added features since he purchased his. Cheaper too!

BTW, most sensitive gate SCRs can be wrung out using the Diode test function provided with most DMMs. Though, not nearly as much fun to do as those (uC based) component analyzers.

Chris
 

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How can i add an LED as an output with the buzzer after all lives have been used? Also, how can i make this LED to be constantly flashing?
 

CDRIVE

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FYI, when you wait a month in between posts some of us forget where we were and what we're discussing. This may be the only project you've got on the fire but those of us that are here solely for assistance to others have embedded themselves in many topics since your last post.

Chris
 

(*steve*)

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How can i add an LED as an output with the buzzer after all lives have been used? Also, how can i make this LED to be constantly flashing?

Use a microcontroller.
 

FuZZ1L0G1C

Mar 25, 2014
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9VDC is the supply, but your wire-loop trigger SW2 will be at around 5VDC max between IC1[2] and Gnd (0V).
A human's hand-hand skin resistance can vary from dry skin at about 100K to sweaty at around 1K.
This translates to a maximum DC current (I=V/R) of 50uA to 5mA.
According to wiki/electric shock (info), to feel a sensation of DC current, minimum 5mA is required.
AC (at 60 Hz) requires a minimum of 1mA.
For DC current, its unlikely the gamer would feel anything, especially as the hand-loop is only one side of the circuit.
If the loop is dragged over the wire, the electrical 'noise' may simulate a low-voltage (max 5Vpp) "AC" waveform.
However, the R1/C1/R2 network would likely suppress most spikes.
In summary: no danger, no shock.
Tongue-in-cheek(y) suggestion:
When working with HT voltages of 5V DC, take appropriate safety precautions: Chevron danger-tape, rubber gloves, face-shield, emergency personnel. ;)
 

FuZZ1L0G1C

Mar 25, 2014
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ADD: if dragging the loop causes noise 'ripple', at most you may feel a slight tickle - definitely not lethal.
As a young kid, I touched my bicycle's 6V AC lamp-dynamo [out] pin while riding - the slight AC ripple surprised me, but nothing major.
If you know a friendly fridge/aircon tech, the thin (5-6 mm) copper tube is quite sturdy, able to bend by hand.
 

FuZZ1L0G1C

Mar 25, 2014
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Regarding the series Rs LED droppers:
As 4017 sequences 10 outputs (5 in this case), duty cycle is 1:5 (or 5:1?) so any one LED will be [1] for t=20% and [0] for t=80%, allowing the diode's junction to cool for 80% of the time.
If you opt to use all 10 outputs Q0-Q9 then this is 10%/90% on/off cycle. Q10 now reset latch to R.
So provided Vd of LED (or series leg of Vdtot) is around 5V, the circuit can work for limited periods without Rs.
That being said, repeatedly overloading the LED will make it die a premature and painful death.
Unless you really need a bright display, suggest you follow Rs advice (which it sounds like you've already done).
If you want more LED's you could series them per leg (identical values per leg), total Vd up to the 5V output.
Vd=Forward voltage drop of one LED.
Vdtot=Vd*qty (e.g: 1.7*2 = 3.4 V)
Vdiff=Vout-Vdtot
If=LED Forward current
Rs=(Vout-(Vd*qty))/If
So for, say 2* 1.7V 20mA LED's per leg,
Rs=(5-(1.7*2))/0.02 = (5-3.4)/0.02 = 1.6*50 = 80 R
80 ohms not a standard value, nearest is 82 R.
U/B white LED's if I remember are 3V 30mA.
 

Audioguru

Sep 24, 2016
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The LEDs are not shorted to the 9V battery, they are driven with a fairly low current CD4017 IC. The Texas Instruments datasheet for a CD4017 shows a typical output current of 20mA into a dead short or 17mA into a 3.5V LED. But the max allowed dissipation in an output transistor is 100mW which is 7V at only 13.9mA (a new 9V battery and a 1.8V red LED).CD4017 driving an LED.PNG
 
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