hi
i have a project in AVR(attiny2313) and i want use 4 big 7 segments,what is the most suitable circuit for link 7 seg with my circuit....
note:i have 2 voltages 5,12 VDC
plz. help

 

You'll need to multiplex them. Something like a CMOS CD4511 for a decoder would also be helpful, I believe the data sheet here has some good suggestions. That and some darlingtons to handle individual digits.

Just searching I found this website.

I found the datasheets through the electronic resources forum.

 

Be careful with those big 7-segment displays. You really need current regulation for each segment.

I bought some red 4" 7-segment displays from an online auction. Segments a thru g required about 11.4 Vf (forward voltage) for 25mA, and the DP was 5.7Vf at 25mA.

You CAN use resistors, but verify what your Vf is for each segment using a constant current source before you hard-wire them in.

After you verify Vf, then:
Rlimit = (VoltageSupply - Vf) / LEDcurrent
Then calculate the wattage required for the limiter resistors:
W(Rlimit) = (VoltageSupply - Vf) x LEDcurrent x 2
Then round up to the next higher wattage resistor available (eg: 1/10, 1/8, 1/4, etc)

 

Be careful with those big 7-segment displays. You really need current regulation for each segment.

I bought some red 4" 7-segment displays from an online auction. Segments a thru g required about 11.4 Vf (forward voltage) for 25mA, and the DP was 5.7Vf at 25mA.

You CAN use resistors, but verify what your Vf is for each segment using a constant current source before you hard-wire them in.

After you verify Vf, then:
Rlimit = (VoltageSupply - Vf) / LEDcurrent
Then calculate the wattage required for the limiter resistors:
W(Rlimit) = (VoltageSupply - Vf) x LEDcurrent x 2
Then round up to the next higher wattage resistor available (eg: 1/10, 1/8, 1/4, etc)

thanks alot,