Question about "turning on computer" without a case.

[purbeast0]

Hey with the diagram you made, does the polarity of the capacitor matter?

 

[sdifox]

Hey with the diagram you made, does the polarity of the capacitor matter?

Stripe side is negative.

Polarity in Electronic Components | West Florida Components

Determining the polarity of an electronic component

www.westfloridacomponents.com

.

 

[purbeast0]

Stripe side is negative.

Polarity in Electronic Components | West Florida Components

Determining the polarity of an electronic component

www.westfloridacomponents.com

.

But your diagram it looks like both sides are a stripe.

 

[purbeast0]

Okay so far this ain't working and I'm guessing I am just doing something wrong. Here is a pic and hopefully you can make it out. When I connect the battery positive and negative, nothing happens. Check out the 2nd pic for the full setup.

EDIT:

Jus realized I did not add the second resistor for the LED but I just tried that and no dice. So I think I'm clearly missing something here.

 

[sdifox]

But your diagram it looks like both sides are a stripe.

The diagram is using standard component representations.

 

[purbeast0]

The diagram is using standard component representations.

Are you saying that just the negative pin of the cap is used here then? I see 2 stripes, no curved lines in your diagram.

Or does polarity not matter in that instance?

 

[sdifox]

Are you saying that just the negative pin of the cap is used here then? I see 2 stripes, no curved lines in your diagram.

Or does polarity not matter in that instance?

No, that is the symbol for capacitor when you see electrical diagrams. When I said stripe side, that is referring to the actual capacitor you brought, not the logical representation.

Can you take a top view and one from the fghij side of the breadboard?

 

[purbeast0]

LOL I just blew an LED because I just put the battery to the + on the LED and the ground to the - on the LED just to try it and it straight up blew it. Glad they came in 3 packs lol.

 

[sdifox]

LOL I just blew an LED because I just put the battery to the + on the LED and the ground to the - on the LED just to try it and it straight up blew it. Glad they came in 3 packs lol.

I have hundreds of LED xd

 

[purbeast0]

I have hundreds of LED xd

If I had a resistor in line would it have not blew the LED?

Pics coming in a sec.

 

[purbeast0]

Sorry my lighting blows.

 

[sdifox]

If I had a resistor in line would it have not blew the LED?

Pics coming in a sec.

Yeah that is why I said resistor +led

 

[purbeast0]

Yeah that is why I said resistor +led

Yeah I just did an LED with 2 AA batteries, a resister on the negative side of the LED and it worked. I just wanted to see that work since I saw it in that tutorial video. That was neat just to see it working lol.

 

[sdifox]

your transistor is not wired right. I should have changed the numbering on the pins in the diagram.

2N3906 Transistor Pinout Details, Equivalent, Technical Specs & Other Details - Components Info

2N3906 is a widely used PNP transistor; the post below describes its pinout details, equivalent, technical specs & other details of this transistor.

www.componentsinfo.com

with the flat side of the transistor facing you, left most pin (1) is emitter, which corresponds to the number 2 connection on the transistor in the diagram I drew. middle is Base, so number 1 connection in the diagram and the last one is collector.

Your capacitor looks flipped as well.


slightly updated diagram to use the right transistor symbol, now the pins on it matches your part. I grabbed a random pnp transistor before. Also, resistor symbol may be shown as a jagged line as well.





these are super convenient for prototyping, and colourful so it is easier to trace

40pcs 20cm Pin Header Dupont Wire Color Jumper Cable Arduino Male to Female/Male | eBay

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but you don't need to get them unless you are going to dive into electronics. just a random example from ebay, not recommending or anything.

 

[purbeast0]

your transistor is not wired right. I should have changed the numbering on the pins in the diagram.

2N3906 Transistor Pinout Details, Equivalent, Technical Specs & Other Details - Components Info

2N3906 is a widely used PNP transistor; the post below describes its pinout details, equivalent, technical specs & other details of this transistor.

www.componentsinfo.com

with the flat side of the transistor facing you, left most pin (1) is emitter, which corresponds to the number 2 connection on the transistor in the diagram I drew. middle is Base, so number 1 connection in the diagram and the last one is collector.

Your capacitor looks flipped as well.

The flat side of it is facing away from the IC chip, not towards it. So the 1 pin is in d5 in the pic I showed you, so I think it is correct no?

Pin 3 is in d7 and pin 1 of the IC chip is in e7.

EDIT:

Oh shit I misread your post. Okay let me give that a go.

 

[purbeast0]

Hmm I flipped pins 1 and 2 in the transistor in the diagram and still no luck. I tried both capacitor directions too and nothing.

I'm still confused as to where the negative/positive of the capacitor goes though from the diagram. I'm not understanding how to know which direction is positive/negative from the diagram.

 

[sdifox]

Hmm I flipped pins 1 and 2 in the transistor in the diagram and still no luck. I tried both capacitor directions too and nothing.

I'm still confused as to where the negative/positive of the capacitor goes though from the diagram. I'm not understanding how to know which direction is positive/negative from the diagram.

positive side is from the wire, the negative goes to the transistor base pin. The shorter leg is the negative.

Polarity - SparkFun Learn

 

[purbeast0]

I just redid it and moved some stuff around to get a little bit more space and still no dice. I know in the pic the capacitor is backwards from what you just said in your post, but I tried it the other way and still seems to not do anything for me.

 

[sdifox]

I am an idiot... Should have picked NPN transistorand not PNP... let me think about how to change the circuit to use PNP in the mean time.

How Transistors Work (BJT and MOSFET) - The Simple Explanation

A transistor works like a switch. It can turn ON and OFF. Or even "partly on", to act as an amplifier. Learn how transistors work below.

www.build-electronic-circuits.com

 

[purbeast0]

I am an idiot... Should have picked NPN transistorand not PNP... let me think about how to change the circuit to use PNP in the mean time.

How Transistors Work (BJT and MOSFET) - The Simple Explanation

A transistor works like a switch. It can turn ON and OFF. Or even "partly on", to act as an amplifier. Learn how transistors work below.

www.build-electronic-circuits.com

Hah okay well if it requires more parts other than what I already have, then it may not be worth it. I know Microcenter had the PNP stuff as well I believe so I could always go get it. This stuff is way over my head but very interesting none the less so if you can figure it out with the stuff I have I definitely will give it a go. It's very interesting to me and thanks for all the help thus far.

 

[sdifox]

you only have 4 resistors so I could not drop the voltage further for the bias. Give this a try. the ground after R3 and R4 is just the negative of the battery.



or like Squirrel said, microcontroller.

do you have a multimeter? that would help in debugging circuit.

 

[purbeast0]

you only have 4 resistors so I could not drop the voltage further for the bias. Give this a try. the ground after R3 and R4 is just the negative of the battery.
View attachment 22467


or like Squirrel said, microcontroller.

do you have a multimeter? that would help in debugging circuit.

Just tried this and still didn't get anything

I am super tired though and will double check it tomorrow morning.

If you are like 95% positive that the NPN transistor will work with the first one I will run to Microcenter tomorrow and grab one. It's like $1 and 10 minutes away so it's not a big deal.

 

[sdifox]

I think it has to be a NPN since with the PNP when you power on the circuit the base (pin2) is close to 0 v thus power from pin 1 will pass to pin 3, making the xor gate output 0.

 

[purbeast0]

I think it has to be a NPN since with the PNP when you power on the circuit the base (pin2) is close to 0 v thus power from pin 1 will pass to pin 3, making the xor gate output 0.

How confident are you that will make it all work

If high I'll run there later on and get those and give it a try.

Just googling these things and not knowing a thing about them yesterday, I see the difference between the two and how easily it would be to mix them up.

EDIT:

Reading your comments again and reading a little about transistors and starting to make sense of it, are you saying that pin 1 of the XOR will be 1 from the transistor pin 3 and then 1 from the AC on pin 2 of the XOR, thus making the total result of the XOR being 0 and not opening?

And that with the NPN resistor, the transistor pin 3 would have 0 value passed to pin 1 of the XOR and then 1 from the AC to pin 2 of the XOR and the total result of XOR will be 1, thus completing the circuit?

 

[sdifox]

How confident are you that will make it all work

If high I'll run there later on and get those and give it a try.

Just googling these things and not knowing a thing about them yesterday, I see the difference between the two and how easily it would be to mix them up.

EDIT:

Reading your comments again and reading a little about transistors and starting to make sense of it, are you saying that pin 1 of the XOR will be 1 from the transistor pin 3 and then 1 from the AC on pin 2 of the XOR, thus making the total result of the XOR being 0 and not opening?

And that with the NPN resistor, the transistor pin 3 would have 0 value passed to pin 1 of the XOR and then 1 from the AC to pin 2 of the XOR and the total result of XOR will be 1, thus completing the circuit?

With a NPN, the initial state of pin 3 will be 0, which will result in inputs to XOR being and 0 which gives you 1 on the output of the XOR.
This in turn feeds the base of the transistor and make it go to on state, which allows 5V to flow to the XOR. At this point both input of the XOR are 1, resulting in output of 0.

Shit. It's going to flick on again after cap drain. The circuit is wrong. I got to rethink. The temporary connection while maintaining power to the circuit is really tricky.

There is a reason a push button is easy xd.