Help with LED circuit

[Guitarnut]

Here's what I'm trying to figure out.

 

[Guitarnut]

I breadboarded the radio button circuit today. It seems to be working okay. If I can get the switches figured out, I'll be in goo shape for a full footswitch prototype.

 

[Guitarnut]

I sorted the issue with the DPDT momentary switches. I just wasn't pressing the switch fully. My SPST momentary switches are soft touch. No click. The DPDT momentary do. When I fully engage the switch, it clicks and makes proper connections. So, drum roll....I'm good for what I want to do. 2 poles, single action. Perfect.

Updated drawing:

 

[ratstar]

Making a computer is the same, you just have to get the LEDs to fire the right way.
Is that your schematic? It looks nice and neat.
Nice job.

 

[Guitarnut]

Making a computer is the same, you just have to get the LEDs to fire the right way.
Is that your schematic? It looks nice and neat.
Nice job.

Thanks. The one just above in post #23 is mine. The original radio button schematic that I started from in post #10 was provided by AnalogKid.

 

[Guitarnut]

Well, as I've moved this project forward, I've good success getting the circuit soldered onto a solder-type breadboard so everything is firmly in place. It's working as expected but the LEDs aren't very bright. I started B+ at 3.5v and went up to 7.5v and they increased a bit but not what I expected. Max supply voltage for the 74AC574 is listed at 7v with max input voltage being Vcc +.5v. They flash super bright when a switch is pushed but then dim down when they latch. I wonder if adjusting a few component values would solve the problem. Any suggestions would be greatly appreciated.

 

[Guitarnut]

A reminder of the components and values being used.

 

[bertus]

Hello,

Did you cut some traces?


Bertus

 

[Audioguru]

Pin 10 (0V) and pin 20 (positive supply) of the CD74AC574 are not connected to the power supply.

 

[Guitarnut]

Hello,

Did you cut some traces?
View attachment 50189

Bertus

The traces with Xs have been cut and verified.

 

[Guitarnut]

Pin 10 (0V) and pin 20 (positive supply) of the CD74AC574 are not connected to the power supply.

Ah, that wasn't in the original schematic. My ignorance showing.

 

[Guitarnut]

I connected pin 10 0v, and pin 20 B+. (red jumpers) But, now the LEDs are plenty bright when a switch is pressed but they no longer latch.
Ugh!

 

[Guitarnut]

Question: What is the significance of the portion of the circuit labeled Startup? Circled in red.

 

[Audioguru]

You have the inputs pins 6, 7, 8, and 9 of the 74AC574 floating instead of connected to ground.
Pin 3 and pin 8 of RN1 have an X instead of as shown in the schematic.

 

[Guitarnut]

Thanks. I'll get this corrected tomorrow.

 

[Guitarnut]

You have the inputs pins 6, 7, 8, and 9 of the 74AC574 floating instead of connected to ground.
Pin 3 and pin 8 of RN1 have an X instead of as shown in the schematic.

If pins 6-9 are connected to RN1 as shown in the schematic, do they still need to go to ground? I've rearranged the layout so U1 pins 2-9 are connected to RN1. Is either of these correct?

 

[Audioguru]

Sorry, I was wrong before.
Do not connect pins 6, 7, 8 and 9 of the IC to ground, instead connect them to RN1 if the linger RN1 is the same as the short RN1.

 

[Guitarnut]

Sorry, I was wrong before.
Do not connect pins 6, 7, 8 and 9 of the IC to ground, instead connect them to RN1 if the linger RN1 is the same as the short RN1.

Perfect. Thank you!