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Custom power switch questions

Struda

So, I am not far off ascending to the master race (waiting on a couple of parts), and am wanting to build a custom power switch to go with my new toy. I had an idea in mind, but I don't know how possible it is.

I've attached a basic plan of what I want, similar to a pilot starting the engine on a jetliner. I know i could do a simple circuit but this would be so cool

1. 2 dial switches and a shielded switch (SW1-3)

2. You then hold down SW5 and a red diode will turn on, along with a scream from a dc buzzer.

3. Whilst holding down SW5, turn the key on SW4, also a momentary switch.

 

The issue I see is not enough voltage going to the buzzer, or too much getting through and the computer starting up. Kinda a pipe dream at this stage, but would be so cool in my opinion. Also it will be wired to a small box external from the case

Screen Shot 2019-03-19 at 1.48.39 pm.png

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@Struda

how is this connected to the power switch? can't see any relation to it?

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you can use a relay for the buzzer but just the buzzer would need it's own power supply or battery due to the pc's power supply not being on before the machine is on

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14 minutes ago, Struda said:

So, I am not far off ascending to the master race (waiting on a couple of parts), and am wanting to build a custom power switch to go with my new toy. I had an idea in mind, but I don't know how possible it is.

I've attached a basic plan of what I want, similar to a pilot starting the engine on a jetliner. I know i could do a simple circuit but this would be so cool

1. 2 dial switches and a shielded switch (SW1-3)

2. You then hold down SW5 and a red diode will turn on, along with a scream from a dc buzzer.

3. Whilst holding down SW5, turn the key on SW4, also a momentary switch.

 

The issue I see is not enough voltage going to the buzzer, or too much getting through and the computer starting up. Kinda a pipe dream at this stage, but would be so cool in my opinion. Also it will be wired to a small box external from the case

<snip>

doesn't have to be a pipe dream, its a neat idea, what are the dial switches for?

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Just now, CodeNova said:

doesn't have to be a pipe dream, its a neat idea, what are the dial switches for?

coolness factor

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21 minutes ago, _Syn_ said:

coolness factor

Right, but do they serve a purpose? I didn't know if you were going for like a 'combination lock' type thing. So they are 'just for looks'?

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1 minute ago, CodeNova said:

Right, but do they serve a purpose? I didn't know if your were going for like a 'combination lock' type thing. So they are 'just for looks'?

i'm not him, sorry i replied xD but yeah that's what i understood he's trying to achieve, kinda like that scene from Back To The Future when Marty is powering on the amplifier.

 

as you can see SW1 (dial) SW2 (dial) SW3 (switch) are all connected in series, but he can do a combination lock with that configuration though, that's an awesome idea

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10 minutes ago, _Syn_ said:

i'm not him, sorry i replied xD but yeah that's what i understood he's trying to achieve, kinda like that scene from Back To The Future when Marty is powering on the amplifier.

 

as you can see SW1 (dial) SW2 (dial) SW3 (switch) are all connected in series, but he can do a combination lock with that configuration though, that's an awesome idea

Your fine, any reply is a good reply. I was gonna suggest he could do something with some discrete logic chips, maybe a bjt to control the power jumpers on the motherboard. Maybe a dc buzzer, or a 555 connected to a small speaker.

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20 minutes ago, CodeNova said:

Your fine, any reply is a good reply. I was gonna suggest he could do something with some discrete logic chips, maybe a bjt to control the power jumpers on the motherboard. Maybe a dc buzzer, or a 555 connected to a small speaker. 

damn that's alot of cool ideas, but depending on his expertise or interest in this kind of thing, I think a buzzer and a relay would do fine, but he can definitely mess around with the configuration of the switches :D

 

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2 minutes ago, _Syn_ said:

damn that's alot of cool ideas, but depending on his expertise in this kind of thing I think a buzzer and a relay would do fine, but he can definitely mess around with the configuration of the switches :D

 

*nods* I agree.

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1 hour ago, _Syn_ said:

@Struda

how is this connected to the power switch? can't see any relation to it?

The current/voltage input on the right of the circuit is meant to be the motherboard

39 minutes ago, CodeNova said:

@Struda How do you fell about using a micro controller? or a cheap Arduino clone?

Honestly would have no idea how to start but would be keen to try if i couldn't get it done with a simple circuit

 

52 minutes ago, _Syn_ said:

i'm not him, sorry i replied xD but yeah that's what i understood he's trying to achieve, kinda like that scene from Back To The Future when Marty is powering on the amplifier.

 

as you can see SW1 (dial) SW2 (dial) SW3 (switch) are all connected in series, but he can do a combination lock with that configuration though, that's an awesome idea

Thats exactly the idea I had in mind hahah

 

Thanks for all the ideas everyone, having looked into relays and that its going to be external to the pc, I think thats a good place to look more into

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3 minutes ago, Struda said:

The current/voltage input on the right of the circuit is meant to be the motherboard

Just so we are on the same page, the power switch is just an open circuit and you turn on the PC by shorting it out, it doesn't actually provide 12V

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kinda confused so i had to say it

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6 minutes ago, _Syn_ said:

Just so we are on the same page, the power switch is just an open circuit and you turn on the PC by shorting it out, it doesn't actually provide 12V

That makes sense, I didnt think it could be done with a parallel circuit because either one would short it

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is this a more realistic model?

switches 1,2 and 3 must be on, then switch 5 pressed before switch 4 will work. MB at power on left, on right either a battery pack or repurposed cable

Screen Shot 2019-03-19 at 3.40.49 pm.png

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7 hours ago, Struda said:

is this a more realistic model?

switches 1,2 and 3 must be on, then switch 5 pressed before switch 4 will work. MB at power on left, on right either a battery pack or repurposed cable

Don't understand what you're trying to do there sorry :/ i was thinking more of something like this

 

1000566326_ScreenShot2019-03-19at1_48_39pm.png.111f9aca0ae1eada9aecc8e213858a8a.png.d5366df96a40c80d6b7d3085b1f0b850.png
 

Sorry don't have circuit designer applications installed :D so had to use good ol' paint, i'm a little rusty on these things so i would like a confirmation on this @CodeNova, though i think that it would work fine this way

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13 minutes ago, _Syn_ said:

Don't understand what you're trying to do there sorry :/ i was thinking more of something like this

 

<snip>
 

Sorry don't have circuit designer applications installed :D so had to use good ol' paint, i'm a little rusty on these things so i would like a confirmation on this @CodeNova, though i think that it would work fine this way

From what I can tell at quick glance.

- There should be a current limiting resistor on the led.

- DC wont work on an 8 ohm speaker.

- There should probably be a current limiting resistor on the relay too.

- sw1-sw3, when they all close that's a dead short. (bye power supply)

It really is a great start though, when I have time today ill look at it more closely.

I'm a bit rusty myself, no worries.

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11 minutes ago, CodeNova said:

- sw1-sw3, when they all close that's a dead short. (bye power supply)

oof.. :D completely overlooked

 

11 minutes ago, CodeNova said:

- DC wont work on an 8 ohm speaker. 

From what i understand from him that speaker is supposed to be a buzzer



it's a start atleast :D i have all the components so i can test this later actually

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@_Syn_ @Struda

Functionally, how dose something like this look?

(its a work in progress)

image.png.0b3a82f2c80ea800d8b4c4b4a23b2c4a.png

part count is minimal, and cheap.

Let me know what you think. I'm not 100% sure about the buzzer, the one I was viewing as a reference was rated at 20mA.

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25 minutes ago, CodeNova said:

Functionally, how dose something like this look?

This looks pretty good, the process is what i had in mind :D the gates are a good idea to not let you cheat and skip ahead, but wouldn't the second gate be bypassed because of the buzzer? also what does the 1N4148 exactly do?

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1 minute ago, _Syn_ said:

but wouldn't the second gate be bypassed because of the buzzer?

though i guess not because of ground and the resistor

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27 minutes ago, _Syn_ said:

though i guess not because of ground and the resistor

The 1N4148, in this case, is a 'flyback diode'. It has something to do with minimizing voltage spikes on the relay coil (I had to look it up). I know its good practice to pair a relay with a diode, I just never really knew why. I'm pretty sure the second gate cant be bypassed, Ill take another look at it, its been awhile since I've had to layout with discrete logic, everything's all digital now.

Edit: I got spoiled with mcu's

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52 minutes ago, CodeNova said:

The 1N4148, in this case, is a 'flyback diode'. It has something to do with minimizing voltage spikes on the relay coil (I had to look it up). I know its good practice to pair a relay with a diode, I just never really knew why. I'm pretty sure the second gate cant be bypassed, Ill take another look at it, its been awhile since I've had to layout with discrete logic, everything's all digital now.

Edit: I got spoiled with mcu's

Oh okay that makes sense, and yeah i'm sure the second gate can't be bypassed because of the ground connection, I spoke too quickly

This should be simple enough to do, he can also replace S4 with a Potentiometer for the LED to glow slowly, good job man 

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3 minutes ago, _Syn_ said:

Oh okay that makes sense, and yeah i'm sure the second gate can't be bypassed because of the ground connection, I spoke too quickly

This should be simple enough to do, he can also replace S4 with a Potentiometer for the LED to glow slowly, good job man 

I just enjoyed the conversation, I'll be kicking around on here for a bit if you can think of anything else. It was nice talking to you.

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