Ice Tube Clock display flickering

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chanakaya
 
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Ice Tube Clock display flickering

Post by chanakaya »

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Hi,

I have had the Ice tube clock working fine for the past few months. Since the past month, the display has started flickering, becomes progressively worse and eventually turns off. If I turn off the power and then turn it back on, the display comes back on fine for sometime and then the flickering starts again. Any ideas on what could be wrong and suggestions to fix it will be greatly appreciated.

--chanakaya

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MikeHg
 
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Re: Ice Tube Clock display flickering

Post by MikeHg »

May be a defect Q3? You could try to shortcut Q3 and see what happens.

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adafruit_support_bill
 
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Re: Ice Tube Clock display flickering

Post by adafruit_support_bill »

That could be a Q3 issue. Q3 controls the heater bias current to the tube to reduce power demands when running from the backup battery. If you short the two outer pins of Q3 together, it will bypass Q3. If shorting Q3 results in a steady display, we can look into the options for fixing it.

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chanakaya
 
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Re: Ice Tube Clock display flickering

Post by chanakaya »

Thanks Mike and Bill,

It looks like that was it. With Q3 shorted, the flickering is gone. Please let me know on next steps.

--chanakaya

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adafruit_support_bill
 
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Re: Ice Tube Clock display flickering

Post by adafruit_support_bill »

If you contact [email protected] with a link to this thread we can send a replacement Q3.

Several form members have developed alternative solutions with commonly available parts. If you are interested, this thread has more info on that: http://forums.adafruit.com/viewtopic.ph ... =q3+mosfet

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MikeHg
 
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Re: Ice Tube Clock display flickering

Post by MikeHg »

May be you want to choose the PN2907A / 1k resistor combo. I used the equivalent 2N2907A, which has a metal cap (see picture).

This combination works quite well and is not as sensitive as the MOSFET.

Regards,
Mike
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chanakaya
 
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Re: Ice Tube Clock display flickering

Post by chanakaya »

Thanks Mike. I am going with the replacement from Adafruit. If that fails, I will try your suggestion.
regards,
chanakaya

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