Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

3 Input/output LDR cicuit required??

Status
Not open for further replies.
Techyman said:
Hi
I need a 3 input LDR circuit with 3 LEDs as outputs for my GCSE project.

Hi Techyman! Welcome to the forum.

Can you post what you have so far and what problem you're having so we can check it out and try to give you a hand? Without that we don't really have a place to start.

We could just make one for you but that would defeat the purpose of the project. :)


Torben
 
3 input ldr

the idea was to have a childs toy abit like a jigsaw -when you added the shapes,which would cover an ldr an led would then light up -image of type of toy can be seen here-http://www.elc.co.uk/category-536 -the blossom farm puzzle-thanks for helping-
 
Techyman said:
the idea was to have a childs toy abit like a jigsaw -when you added the shapes,which would cover an ldr an led would then light up -image of type of toy can be seen here-http://www.elc.co.uk/category-536 -the blossom farm puzzle-thanks for helping-

OK, so how far have you gotten? What does your current schematic look like? Have you tried it out on a breadboard yet?

Also, what course is this for, and have you covered transistors yet?


Torben
 
This is for a GCSE Technology and Design course in Northern Ireland exam board being CEA - I have covered night light circuits using ldrs and variable resistors with a tip 121 transistor
 
Techyman said:
This is for a GCSE Technology and Design course in Northern Ireland exam board being CEA - I have covered night light circuits using ldrs and variable resistors with a tip 121 transistor

Wouldn't you then just need three of those? Or do you need to use a microcontroller or something?


Torben
 
You also need to consider the lighting conditions when designing this. If it's used in a dimly lit room then all the LEDs could turn on.

Here's some more information regarding omparators.
**broken link removed**

Also, please remember to sight your resources so you don't get accused of cheating. Inclued links to this website and to the datasheet and link I've provided with your project.
 
circuit diagram

where would i find a circuit digram/component values for this so i can draw it using crocodile technology and then convert it using the pcb wizard software?

1 LM339
1 potentiometer
3 LDRs
6 resistors
3 LEDs
1 battery
1 switch
 
you can fix this in some ways by using IR parts as well to ensure light hits the LDRs, even if its not visible light.

no idea what crocodile tech is.

the data sheet should have the information required.
 
Techyman said:
where would i find a circuit digram/component values for this so i can draw it using crocodile technology and then convert it using the pcb wizard software?

1 LM339
1 potentiometer
3 LDRs
6 resistors
3 LEDs
1 battery
1 switch
Have you checked the link I provided in my previous post?

Have you checked the datasheet for the LM339 (this can be found using Google)?

Have you read Crocadile Technology's help file?

Have you showed this forum to your teacher?
 
found a schematic!

would this be a good starting point?- see attachment
 

Attachments

  • LM 339.jpg
    LM 339.jpg
    44.4 KB · Views: 631
Yes, that's the sort of thing you're looking for.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top