Help and advises for two LED's driving circuit.

MikeMl

Well-Known Member

Most Helpful Member

• Apr 1, 2016

• #21

I have lots of two-pin bi-color LEDs around here... These two-pin red-green LEDs are available from DigiKey. They should be readily available from Bangood or EBay.

If you must use a three-pin LED, it would be easier to redesign the circuit to use a common-anode, rather than a common-cathode one like you show.

 

M

milkoni

Member

• Apr 1, 2016

• #22

Thanks Mike,
I understood, but I have some three-pin LEDs - about 20, with common cathode and would like to use them. I'm going to try to change the circuit.

 

M

milkoni

Member

• Apr 1, 2016

• #23

May be this is not a elegant solution, but it seems that will work with my three-pin common cathode LEDs.

 

Attachments

• map_sensor_led_indicator_TL431_BiColor_v2.png

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MikeMl

Well-Known Member

Most Helpful Member

• Apr 1, 2016

• #24

Looks similar to what I was working on. Check the sensitivity to variations in the 12V power supply as I am doing here:



Yours has a bit more Amber in the overlap.

 

Last edited: Apr 1, 2016

M

milkoni

Member

• Apr 1, 2016

• #25

I think that your decision is better!

 

M

milkoni

Member

• Apr 16, 2016

• #26

Hi all,
I've decided to build a circuit for MAP sensor indicator with a LM3914. It working fine, but in dot mode the first diode always lights smoothly. How to resolve this problem?
I've attached the simulation image and circuit file.

 

Attachments

• map_sensor_led_indicator_LM3914.png

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• map_sensor_led_indicator_LM3914_v2.asc

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Last edited: Apr 16, 2016