# Tag Info

### Turn ON LED that behaves like OR gate with the same intensity

This is a way to limit the current through D3 to approximately 30mA, which is not quite what you asked for: simulate this circuit – Schematic created using CircuitLab The TL431 circuit is ...
• 409k

### Turn ON LED that behaves like OR gate with the same intensity

No. You have defined a hypothetical question with some current-mode logic using diodes combined into one so-called "diode-OR" voltage logic. That would violate Kirchoff Laws to do what you ...
• 146k

### LEDs driven by constant-current drivers to light up like AND gates with the same intensity

Okay, if I take your circuit and flip it upside down to accommodate the LED connections with the TLC5947 and 24V VLED that you are using, and add a bit of circuitry and much smaller MOSFETS to protect ...
• 409k
1 vote

### LEDs driven by constant-current drivers to light up like AND gates with the same intensity

I think the following circuit will do what you want, but I haven't tested it physically. It's a lot simpler than yours (which I believe would work, by the way), requiring no additional power supply, ...
• 40k

### LEDs driven by constant-current drivers to light up like AND gates with the same intensity

The circuit in the original question should work fine. To simplify, you can delete R2, R4 and R5. Connect the Q1 gate directly to the R1 / D1 node. Connect the Q2 gate directly to the Q1 drain. Not ...
• 21.6k

### LEDs driven by constant-current drivers to light up like AND gates with the same intensity

If you ensure stable 5V supply you can avoid Led drivers and use a 68 ohm limiting resistors instead. An AND gate form a 1K/1K/4k7 resistors here. When both D1&D2 are supplied the transistor ...
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### How important is a "no reflection" strategy for 1 Hz systems?

FWIW, TI's rule-of-thumb for LVC logic is you don't need to add resistors if the traces are less than 4", so the 50mm is well within that limit, even ignoring the fact it's slow-as-molasses ...
• 409k

### How important is a "no reflection" strategy for 1 Hz systems?

The big takeway is that you are using "fast" chips so you have a "fast" design. The fact that the signals through the fast system are 1 Hz signals is irrelevant, because fast chips ...
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### How important is a "no reflection" strategy for 1 Hz systems?

Reflections depend on edge rate and required signal quality; and any extenuating circumstances, like if slow edges cause excessive power dissipation or chattering/oscillation of logic gate inputs, or ...
• 41.2k
1 vote

### Circuit for switching between two AC voltage sources

A relay or a contactor should suffice.
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### Circuit for switching between two AC voltage sources

Are the two AC sources in perfect phase alignment? If not, two things. a) the load might not like an instantaneous voltage change of up to 750 V. b) the two AC sources might not like being connected ...
• 21.6k

### Circuit for switching between two AC voltage sources

That's not going to work. Redraw your circuit using only V1, V2, X1 and replace the SSRs with switches. Now figure out what happens when SSR1 is closed, SSR2 is closed and both are closed. simulate ...
• 178k

### AND Gate from LEDs to drive another LED

8 input NAND with negative logic is required for more choices. There are 6 mA, 20 mA CMOS options and 50 mA TTL level using 74ACT11030N where any fault-in must* be <1V with output to Anode at 5V ...
• 146k

### AND Gate from LEDs to drive another LED

The question is missing some critical details, so this is very much guesswork. Here is a first pass schematic for what I'm guessing is the question. This uses the AND gate suggested by the TS. ...
• 21.6k
1 vote

### AND Gate from LEDs to drive another LED

If I assume you've added series resistors to the existing LEDs that are high enough that the logic levels at the output are still valid (this is an important caveat!) like this: simulate this circuit ...
• 409k

### Power a light only when 2 powered inputs

A relay is the correct thing to use in theory, and probably what you should not use yourself. The vibrations your car is going to expose your relay to is going to make electromechanical relays die ...
Accepted

### Power a light only when 2 powered inputs

Normally, I'd say you'd need 2 relays, but we can make it simpler. First, let's look at the clean and easy solution with two relays: simulate this circuit – Schematic created using CircuitLab ...
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### Power a light only when 2 powered inputs

What's the light you're powering? If it's a simple low-power indication LED, you can just use an AND gate like you've mentioned. You will need to use a current limiting resistor though. You can find ...
• 461
Accepted

### Convert binary number in flip-flop for use with mux select lines?

I think you are asking how to design a decoder. There are many online references on how to do this. For example: (source: https://www.allaboutcircuits.com/textbook/digital/chpt-9/decoder/ ) ...
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