iR based circuit help needed

[Javid.zare.s]

hi everyone, The goal is to make a two part circuit one part is low voltage and should drive my second part which is a hi-voltage AC circuit.
The trigger of low-voltage circuit is an iR sensor and should detect my hands mostly at 20-30cm , when detected it should turn oN (AC part)until I put my hands away. and also I wonder if its possible to make it last longer(example: I flash my hand for a very short period and AC circuit stays oN for 5 seconds more without my hands underneath it)

Here's what I got :
IR light,IR detection (5mm bulby head ), npn and pnp transistor, 555ic ,relays,etc...
what do you think masters? how do you design this circuit

 

[barry]

Sounds like you want us to do your homework for you. Not going to happen.

Show us that you've done something other than collect a box of virtual parts, and then maybe people will be inclined to help.

 

[Javid.zare.s]

Sounds like you want us to do your homework for you. Not going to happen.

Show us that you've done something other than collect a box of virtual parts, and then maybe people will be inclined to help.

no need to spam if you r not going to help or don't know the answer , just in case it's only a diy project that I wanted to build for myself , end of topic, thread closed

 

[betwixt]

The point Barry is making is that we try to help people to solve problems themselves by tutoring them. What we specifically do not do is produce end products for them. If we went down that route we would become a free design team and line peoples pockets at our expense.

What you propose is already done in hundreds of commercial products, for example, water faucets (taps) that flow when hands are placed under them and illuminated mirrors that are activated by waving at them. The principle is simple, an IR source points outwards, an IR sensor points outwards but placed so it cannot see the source directly. An object placed where they can both see it reflects light back and the output from the sensor and triggers a monostable. The monostable is a one-shot timer with it's output controlling the AC. It keeps the AC active during reflection time and for a pre-set time afterwards then turns it off until triggered again. It's very easy to do.

There is a catch though - how do you make it ONLY respond to a reflection from it's own source and not from other IR devices? The answer depends upon where it is going to be used, have a think about it.

Brian.

 

[Javid.zare.s]

The point Barry is making is that we try to help people to solve problems themselves by tutoring them. What we specifically do not do is produce end products for them. If we went down that route we would become a free design team and line peoples pockets at our expense.

What you propose is already done in hundreds of commercial products, for example, water faucets (taps) that flow when hands are placed under them and illuminated mirrors that are activated by waving at them. The principle is simple, an IR source points outwards, an IR sensor points outwards but placed so it cannot see the source directly. An object placed where they can both see it reflects light back and the output from the sensor and triggers a monostable. The monostable is a one-shot timer with it's output controlling the AC. It keeps the AC active during reflection time and for a pre-set time afterwards then turns it off until triggered again. It's very easy to do.

There is a catch though - how do you make it ONLY respond to a reflection from it's own source and not from other IR devices? The answer depends upon where it is going to be used, have a think about it.

Brian.

thanks for reply! and sorry for my last post, iwas angry cause I was waiting a lot for an answer and...
whats a monostable circuit? can it replace my design below?
**broken link removed**
this is what I came up with : I was thinking of 3 parts for triggering (I don't have the knowledge to design, actually its a combination) , part 1 is a light detector circuit which creates a low voltage after light detection ,at part 2: I wanted to take that low-voltage as a trigger for 555 ic to make a toggle switch out of it(to keep circuit alive)
555 turns up the 220v relay ON state and I get A.C
ps. I just tested it in simulation app, and I think in reality the first trigger pulse (from part1)can harm ne555 ic.right?

problems with my design is it stays on until disconnecting whole power(maybe I can fix this) ,but real problem is " not making the delay" (the delay I was telling before)
for solving I tried to replace wiring from toggle switch to timer for 555 but no success