# How Can This Transistor Survive?

Discussion in 'The Projects Forum' started by Artbuc, Jun 8, 2014.

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Jun 8, 2014
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12. ### Artbuc Thread Starter New Member

Jun 8, 2014
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That is what I did. Radio Shack did not have anything higher than a 12 vdc zener. I had the 1N4004 I previously bought from Mouser for D3 so I used it as you suggested. Thank-you.

13. ### Artbuc Thread Starter New Member

Jun 8, 2014
16
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Thank-you all for responding to my posts and for providing this incredible forum. The videos and tutorials are outstanding. My Delay Module seems to be working great with the MPSA06 transistor.

I did use a 550 ohm resistor as suggested to make sure Ib is at least 10% of Ic making it necessary to substantially increase the cap. I calculated it would take about 1.7 secs for the transistor to open with a 1000μF cap. I am not sure how much, if any, delay there is between the transistor opening and the relay opening, but the PTO does not disengage for 3 seconds. I must not be allowing for transients or some other real world effects. I can live with 3 seconds but if I get a rainy day I may drop back to a 500μF cap.

Thanks again!

Last edited: Jun 11, 2014
14. ### Artbuc Thread Starter New Member

Jun 8, 2014
16
0
Sorry, I did not see your post before the previous two. Yes, the input comes from a seat switch. D1 is there to protect against the ignition coil I assume because there is also a similar diode on the starting lug of the ignition switch. During normal operation (on seat with tractor in gear) the ignition module is supplied by D3 through the ignition switch. Do not have a clue why it needs to be 6A. I already had the MPSA06 in hand when I got the previous suggestion to use the 2N2222. Also, I already had 1N4004's. Re the 1k resistor, it would come close to, not meet the Ib/Ic > .1 guideline (if I am understanding the guideline correctly, lol).

You may not be an electronics genius but you sure as heck know a lot more than I do!! Thanks.

Last edited: Jun 11, 2014

Apr 5, 2008
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Hello,

I am closing this thread as it violates AAC policy and/or safety issues.

Quote:
6. Restricted topics.

The following topics are regularly raised however are considered off-topic at all times and will results in Your thread being closed without question:

• Any kind of over-unity devices and systems
• Automotive modifications
• Devices designed to electrocute or shock another person
• LEDs to mains
• Phone jammers
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• Transformer-less power supplies
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