So, 4N35 is an optocoupler. My only problem is that it appears in the schematic that there's an LED inside the optocoupler? I looked this one up and I don't see any hint of one sticking out. Can someone please explain?

 

The LED emitter opto coupler is inside the IC together with the light cell 'transistor' receiver. just a 6 pin device.
Max.

 

Sparkfun is for 5 year olds with lots of money.

 

Sparkfun is for 5 year olds with lots of money.

Why's that? You don't necessarily have to buy the kits, but they offer pretty good free educational material I believe. Do you have a better site for beginners?

 

U generally refers to an IC which can be looked up with a search, the Q usually refers to an inductor, but in this case as mentioned, appears to be a relay coil where it would be the custom to label it R(#) normally.
Edit: Make that RL =relay.
Max.

in my experience, Q is usually a transistor of some type. and L reference for inductors..

 

The LED emitter opto coupler is inside the IC together with the light cell 'transistor' receiver. just a 6 pin device.
Max.

Ditto. Some optocouplers are 4-pin devices, this one has 6 pins. As noted, both discrete components are hidden inside the package just as they are for other ICs.

 

Hello,

In your schematic the buzzer will do nothing, no matter the optocoupler is activated or not.
The output of the optocoupler has no power for the buzzer.

The following pages carry some info on the opto coupler:
http://www.electronics-tutorials.ws/blog/optocoupler.html
http://www.nutsvolts.com/magazine/article/optocoupler-circuits

Bertus

 

U generally refers to an IC which can be looked up with a search, the Q usually refers to an inductor, but in this case as mentioned, appears to be a relay coil where it would be the custom to label it R(#) normally.
Edit: Make that RL =relay.
Max.

Most of the time I have seen Q refer to a transistor.

 

Well sometimes Q can even mean an output.

 

Here is another list, there is no hard and fast set designation, usually the symbol of the device itself is a good indication and better confirmation.
Max.

 

NC mearly means no connection. The other is an inductor, most likely an RF choke.

 

You can still modify the image in a photo editor or print it as black and white.
View attachment 132016

If you are referring to the entire device, it is an opto-coupler. In other words, an optically isolated switch. Turn on the LED in the device and the transistor conducts.

 

Welcome to AAC!

NC mearly means no connection. The other is an inductor, most likely an RF choke.

It would be helpful if you quoted the text that you're responding to so that person will know that you responded to them.

 

If you are referring to the entire device, it is an opto-coupler. In other words, an optically isolated switch. Turn on the LED in the device and the transistor conducts.

Non sequitur... I didn't refer to any optocoupler in that post (#10). It was about editing the schematic in an image editor...

 

Why would there be a diode connected to both terminals of the solenoid?

it's a freewheel doide. https://en.wikipedia.org/wiki/Flyback_diode whenever you run a current through a coil you gotta have a diode there because when you turn that current off, the coil produces an inductive "kick" that must be dissipated. that's how spark plugs work. http://www.chegg.com/homework-help/...tion-engine-generating-asmall-white--q1178057

 

Hello,

In your schematic the buzzer will do nothing, no matter the optocoupler is activated or not.
The output of the optocoupler has no power for the buzzer.

The following pages carry some info on the opto coupler:
http://www.electronics-tutorials.ws/blog/optocoupler.html
http://www.nutsvolts.com/magazine/article/optocoupler-circuits

Bertus

The buzzer isn't actually a buzzer, the person just used it as a stand in. The buzzer is actually meant to stand in for the electric lighter.

 

Hello everyone. I'm rather new to this, and I've never seen a few parts on this schematic. I searched through sparkfuns guide on schematic symbols, but couldn't find what these few were. I pointed them out with black arrows, but I'll also describe part of what I'm talking about. I haven't been able to figure out why some ends are red while other are highlighted in green. The other pieces I can't seem to find. I assume that the red is supposed to connect with red, except that there are multiples and they don't have matching numbers.

Much appreciated,
J

4n35: is an optocoupler
The red lines are open (no connections)
L1: is a choke with an adjustable firite core
Usally found in a shilded can with a hole in the top to. access the core. Ground the can and attach the ends. of the coil to your Circuit.
Then using a plastic (non conducting) screw driver. adjust to the uH needed.

4N35 = Optocoupler

The other one is possibly a relay coil. Would that make sense?

 

it's a freewheel doide. https://en.wikipedia.org/wiki/Flyback_diode whenever you run a current through a coil you gotta have a diode there because when you turn that current off, the coil produces an inductive "kick" that must be dissipated. that's how spark plugs work. http://www.chegg.com/homework-help/...tion-engine-generating-asmall-white--q1178057

... Unless that coil is being driven with AC voltage, in which case the diode will present a short in parallel with the coil on every other half cycle!

Of course, in the context of this schematic you're right, but I thought I should mention the AC problem so that our thread starter doesn't get the wrong idea for future projects.

 

... Unless that coil is being driven with AC voltage, in which case the diode will present a short in parallel with the coil on every other half cycle!

Of course, in the context of this schematic you're right, but I thought I should mention the AC problem so that our thread starter doesn't get the wrong idea for future projects.

Thank you, that's good to know

 

it's a freewheel doide. https://en.wikipedia.org/wiki/Flyback_diode whenever you run a current through a coil you gotta have a diode there because when you turn that current off, the coil produces an inductive "kick" that must be dissipated. that's how spark plugs work. http://www.chegg.com/homework-help/...tion-engine-generating-asmall-white--q1178057

thank you for the simple explanation and the links so i can read more!