I have a working circuit for a retro looking 4 segment incandescent turn signal working incrementally. I am in clear how to edit the circuit to take the first 4 outputs of a 4017 so they latch one adding at a time until all 4 are lighted then all go off to start again. I’m using an adjustable 555 for count, the 4017 turning on mosfets for the current required from an automotive incandescent lamp. I just want to understand how to change my one on at a time and the reset to one on that latches then 2-3-4 then all off.
Thanks for any help.

 

for the current required from an automotive incandescent lamp

Do you need a high-side (12V) or low-side (ground) switch to power the lamps?
That will affect how the circuit is done.

 

Hi Ican,
Is it important that you use a CD4017?
A shift register would be a simple solution.

E

 

Hi Ican,
Is it important that you use a CD4017?
A shift register would be a simple solution.

E

Open to all information….

 

Do you need a high-side (12V) or low-side (ground) switch to power the lamps?
That will affect how the circuit is done.

I’m powering the circuit with 12v and using mosfets that are switching the ground to each lamp

 

Hi Ican
This is the TPIC6595 , note the PDF example circuit.
E

 

Hi Ican
This is the TPIC6595 , note the PDF example circuit.
E

Not seeing any relevant example circuit? Might you have an example?

 

I have a working circuit for a retro looking 4 segment incandescent turn signal working incrementally. I am in clear how to edit the circuit to take the first 4 outputs of a 4017 so they latch one adding at a time until all 4 are lighted then all go off to start again. I’m using an adjustable 555 for count, the 4017 turning on mosfets for the current required from an automotive incandescent lamp. I just want to understand how to change my one on at a time and the reset to one on that latches then 2-3-4 then all off.
Thanks for any help.

You need some OR gates (4071).
Output 1 goes to MOSFET 1
Output 2 and Output1 go to the first OR gate. Gate output goes to MOSFET 2
Output 3 and OR Gate #1 output go to the 2nd OR gate. Gate output goes to MOSFET 3
Output 3 and OR Gate #2 output go to the 3rd OR gate. Gate output goes to MOSFET 4
Output 4 goes to RESET

 

Ian0 are you sure that's the correct arrangment?
I breadboarded the circuit and all 4 LEDs are ON immediately with the first pulse from the 555. Second pulse shuts OFF LED1, third pulse shuts OFF LED2 but so do LEDs 3 and 4 then repeats all ON and so forth.
Besides I believe the TS wanted to go in the opposite direction meaning all OFF when first activated then cycle 1 through 4 with latching.

 

A state diagram or a truth table instead of a verbal description would unambiguously clarify the exact requirements.

 

Version using a CD4071.

 

Version using a CD4071.
View attachment 352621

Off today so I can breadboard both versions. Many thanks. Always loved the mustag I saw with this the turn signal when I was in college many years ago.

 

I breadboarded the circuit in post #11.
The values for C1 and R2 seemed about right for the indicator speed.

 

Here's another circuit.
This uses a CD40174B HEX D-Type Flip flop chip.


EDIT: Removed unnecessary passives.

 

Most shift registers and counters like nice sharp clock edges, slowing down the edge with R2/R3 (post #14) and R4/C4 (Post #11) is going to do more harm than good.

 

I would disagree with that as the clock speed is slow.
I have breadboarded the circuit and using R4/C4 removed some slight glitching.
In a proper built circuit those components may not be required
BTW you never responded to my post #9

 

Most shift registers and counters like nice sharp clock edges, slowing down the edge with R2/R3 (post #14) and R4/C4 (Post #11) is going to do more harm than good.

If you mean R3/C3 post #14, I agree and should have removed them.

 

Edited version from post #11.
Tested using a newer breadboard and is glitch free.

 

This is version using CD4093B NAND Gates (one IC).

 

The circuit shown in post #11 should work IFF the 4071 ICs are able to bias the mosfets into full conduction AND IFF all of the wiring is able to handle the current those bulbs require, which I am thinking is over an amp for each bulb. AND a big caution is that most automotive bulb sockets ground the outside directly.