systems technology project, need circuit help plz. -updated-

[rancid rock]

hey, i hav an idea for a project for this year, it is a fan or a light that comes on when it is a certain temp. or a certain darkness. but also only comes on when there is movement in the area eg. infra red sensors. plz help i hav no clue where to start and hav no circuit diagrams at all.

thanks heaps in advance

 

[akg]

NTC/PTC resistor as temp sensor
LDR as light sensor
and u know "... when there is movement in the area eg. infra red sensors." .

what next .??

 

[rancid rock]

thx mate, there is an update on what i am making. i am now making a small model room with fan that comes on when it is a set temp. and also a light that comes on when it is a set darkness but also only when there is movement. And i am trying to be able to control all of this from outside the room, i may also include a temp sensor so you know what the temperature is inside and outside the room, i just dont know where to start. or if u hav any circuits related to any of the things i hav said.

thx

 

[akg]

thx mate, there is an update on what i am making. i am now making a small model room with fan that comes on when it is a set temp. and also a light that comes on when it is a set darkness but also only when there is movement. And i am trying to be able to control all of this from outside the room, i may also include a temp sensor so you know what the temperature is inside and outside the room, i just dont know where to start. or if u hav any circuits related to any of the things i hav said.

thx

if i was doing that proj, i would start placing the sensors in the room and start building the comparators .

 

[rancid rock]

hmm, yeah that sounds like a fair approach, thx

 

[akg]

hmm, yeah that sounds like a fair approach, thx

keep going ..good luck..

 

[rancid rock]

hmm i am in a sticky situation in this project, i will need a site that has heaps of component symbols and explanations to resolve this.

thx heaps

 

[aibelectronics]

reply

as akg said use NTC thermistors and LDR for the sensors.
you'll need two comparators: one for the thermistor and another for the LDR. you'll then select a reference voltage... then feed the outputs of these comparators to an OR gate, so that if either conditions is met your fan would be put on.
Last but not the least you'll need a relay driver circuit, that would be driven by the output of your OR gate. this section would be a transistor inverter most probably.


as for symbol reference try out "aaroncake's symbol reference ", just google it.

 

[rancid rock]

umm...i'm really srry, i forgot to say i am using a 18X micro controller, i will use it to control everythin in my house model.........

 

[rancid rock]

umm i'll draw up a 3D model quickly of the house and post it asap. so that may help explain exactly what i am tryin to do

 

[rancid rock]

scrap that 3D model idea, too many errors.....i am now also including a burglar alarm and sensor door that only opens when the alarm is off......and im using a 18X micro controller rather than a 28X

 

[William At MyBlueRoom]

I'm assuming you have a PIC 18Fxxx series chip. If it's a 18F2525 you could use it in my Ladybug www.myblueroom.com I/O controller. It has an A/D for light (LDR) and a iButton / 1 wire for temperature www.ibutton.com, also it has a serial port for your PC or whatever & an RS485 for control of other devices. And plenty of spare inputs (for a motion detector) and lots of outputs too.

If you want something prebuilt you might look at the Elk-Magic 443, ADI Ocelot or a JDS Stargate. Read the manuals for them.