Great... *now* you tell me? I literally yesterday ordered a LS JK-flipflop, when it now seems I should have ordered an HC type 😄 Thanks for the good video and explanations!
CMOS outputs can drive TTL inputs, TTL outputs can have problems driving CMOS inputs. HCT inputs CAN be driven with BOTH CMOS & TTL outputs. I use HCT & AHCT 74 series fairly universally mixing them with 74F, 74ALS, & 74LS though if I have the same types available I do not mix bipolar & CMOS devices even though I could.
A relay would be a simple as an AND gate. One pin controls whether the signal on the other pin goes though or not. If you use en inverter infront of that gate you can switch states. If A is high the output goes to _A if B is high the ouput goes to _B. Don't be intimidated by digital circuits. It is really simple once you get familiar with the fundamental gates like AND, OR and INV. Cheers
I'm looking for serial port switcher Assume 1 serial input pin & 2 serial output pin Whenever control pin goes high serial data received on 2nd pin & for low data received on 1st pin(output side)
@@kamals4905 this would be real simple with an AND gate and an Inverter. you tie your control directly to one and gate and through an inverter to another and gate. It would look like this: "Control=1 AND DATA -> output on port one. If control goes to 0, then the inverter would set the other and gate to high and it's input would go through. It is so simple to draw in a picture, but the YT comment section is lacking a doodle function unfortunatly. what is the target freq/edge timing. If i know a little more, that would be helpful.
yes, regarding the levels. no, regarding the timing. if you have a 50MHz SPI connection to analyze, the probe itself could already damage the signal in a certain way. you would then need an active probe which does not influence the circuit too much.
![Introduction - Digital electronics basics: 7400 logic chips [part 1]](/img/n.gif)
I just love the sound of "74xx". It has a certain ring to it.
Yeah i show myself out, thank you :D
Great... *now* you tell me? I literally yesterday ordered a LS JK-flipflop, when it now seems I should have ordered an HC type 😄
Thanks for the good video and explanations!
Just getting into electronics and bought a bunch of logic chips. I just assumed the LS were the best option... *sigh*
Had me laughing at 2:46. I had all those questions.
Thumbs up for getting triggered. :P
Thank you James, good info.
CMOS outputs can drive TTL inputs, TTL outputs can have problems driving CMOS inputs. HCT inputs CAN be driven with BOTH CMOS & TTL outputs. I use HCT & AHCT 74 series fairly universally mixing them with 74F, 74ALS, & 74LS though if I have the same types available I do not mix bipolar & CMOS devices even though I could.
Any logic switches? Like relay's NO & NC
Input selector ic
Like 1 input pin & select 2 other pin(A & B)
If high 1 to A
If low 1 to B
Sounds like you're looking for a multiplexor
A relay would be a simple as an AND gate. One pin controls whether the signal on the other pin goes though or not. If you use en inverter infront of that gate you can switch states.
If A is high the output goes to _A if B is high the ouput goes to _B.
Don't be intimidated by digital circuits. It is really simple once you get familiar with the fundamental gates like AND, OR and INV.
Cheers
I'm looking for serial port switcher
Assume 1 serial input pin & 2 serial output pin
Whenever control pin goes high serial data received on 2nd pin & for low data received on 1st pin(output side)
@@DasIllu I'm searching for faster switching
@@kamals4905 this would be real simple with an AND gate and an Inverter.
you tie your control directly to one and gate and through an inverter to another and gate. It would look like this: "Control=1 AND DATA -> output on port one. If control goes to 0, then the inverter would set the other and gate to high and it's input would go through.
It is so simple to draw in a picture, but the YT comment section is lacking a doodle function unfortunatly.
what is the target freq/edge timing. If i know a little more, that would be helpful.
can you measure these values on a cheap scope?
yes, regarding the levels. no, regarding the timing. if you have a 50MHz SPI connection to analyze, the probe itself could already damage the signal in a certain way. you would then need an active probe which does not influence the circuit too much.
How many intros do you need?
Nice channel 💪
cmos ics are 3 times more expensive than ttl in our country 😂😂😂