Flame sensor, any alternatives?

[ahkumm]

May I know wat is the flame's fequency? I mean I need to know that to choose an IR Receiver Module....

 

[kinjalgp]

You actually don't require to know the flame frequency. Any 2-pin photo-diode without any kind of demodulator can sense flame. Try using photodiodes like PD600 or similar which are very sensitive and has inbuilt signal amplifier.
Do not make use of specialized IR receivers like TSOP1738 or any ot TSOP series. These are meant for receiving modulated IR light.

 

[ahkumm]

PD600 has built in amplifiers? and is PN168 a phototransistor? Can I use a phototransistor instead of a photodiode?

 

[kinjalgp]

You can very well use a photo-transistor.

 

[bogdanfirst]

u know that's very funny.....
u made all these people here have a long talk, and then at the end u "pulled the switch"...
so if i understand u need to build a small model robot for firefighting with something like when it "sees" the candle it will splash water?
that means that the termistor, the termocouple versions will not work beacuse the sensors must be in very close range..am i right?
so i would go for the ir sensor, the easyest method....but still a good flash light would trich it, also if u use it outside and if it's sunny......
so as i said my go is for ir

 

[herbymcduff]

bogdanfirst, you are right about the thermistors, or any thing like that. You need a good range of less than 4 inches from my experience. But maybe thats just the cheap ones. Go Infrared.

 

[ahkumm]

4 legs?

Hey guys, I bought a phototransistor but I have no idea how to use it as it has 4 'legs' (I don't know what it's called, maybe Terminals?)
I don't have the data sheet for the component and on the phototransistor there is only one line of wordings :" Heimann 526" Any idea where can I find help?

 

[herbymcduff]

I would say try a general search on any search engine for it. I didn't have any luck, but maybe you will. Also, when you bought it, did it have any other letters or numbers on the package?

 

[charcoal]

the only problem i can think of with using an ir sensor or phototransistor to detect the flame at a distance is accuracy. most of the ir sensors i have seen are wide angle ones and so would not be able to target whatever you’re using to spray the water that accurately, and also may be triggered by other sources (like nearby incandescent lights).

in addition to setting the voltage threshold high you might want to make a receiving horn for the sensor. it’s pretty simple and just involves taking a piece of flexible plastic, spraying one side with metallic silver paint (or covering with tinfoil shiny side out if you can get a really smooth fit) and rolling it into a narrow cone with the sensor at the small end and the reflective surface on the inside. that way you can increase the accuracy that your robot can pinpoint a source, and also increase the range slightly by sacrificing its field of vision (which can be compensated for by making the robot turn full circle whilst ‘patrolling’ for a fire)

note: silver paint isn't a brilliant reflector of ir radiation, but you can't get much better than the shiny side of ordinatry tinfoil

also, have you considered using a silicon thermopile instead or a generic ir sensor? they tend to be much more accurate and with appropriate use of comparators you can get them to distinguish between body heat, lightbulbs and fires and act accordingly.

(i also tried searching for the phototransistor on various search engines and found nothing. did the shop/catalog you bought it from have any additional info about the item, as this normally inculdes pinouts or examples of usage)

 

[bogdanfirst]

u know, i posted my message a little bit much more time before it appeared , so ......just after he said about the robot.....i dont know why it appeared so late.....hm////
i ll go on ir, i built something like this some time ago, but the sensing conditiones where different.... :shock:

 

[bogdanfirst]

know what i am thinking of? why dont u use 2 sensors, oriented about in the same directio, so if the robot detects a highter signal at one of the sensors, it will turn untill the signal detected is the same on both sensore, so the source of the heat would be on the direction of the sensors, between them....could work, who knows? :lol:

 

[Stephan]

IR sensor Application

Our company has sent an IR sensor to detect the exhaust kitchen device for a big household manufacturer in China.From the results of test and using, this ideal is very goods,it cheaper,more convenient and effectness.Do you need our complete solution?

 

[ahkumm]

help ?

IR Sensors? Which are the recommended ones? And how does it really works?
Btw, I wil be working on wall following to walk through a maze ,what r the recommended ways for this huh?

About the phototransistors, I did a very thorough search on the net but comes up empty! I realli wonder why? Does that mean phototransistors are obsolete?

 

[bogdanfirst]

i dont know, here is what i thought of, to get the presence of fire, and its position, you would need 2 sensors, that mens that the fire is a the same hight of the robot and it only needs to turn left or right. put the sensos at some distance of the robot, so that the robot turns to the one that indicates more flames unti the indication is the same on both sensors and the firre is stright up ahead.
i dont know what you searched for phototransistors, they are still used in small circuits today, even is they are many years old.
there are also ir sensors that incorporate an amplifier too, but those are usually used for modulated ir beans for digital transimtion

 

[ahkumm]

thanks alot

Hey man, thanks alot for all ur advice, I've managed to find some useful phototransistor from Fairchild semiconductor......

and about the 4 pin phototransistor..i've no solution to it!
And from wat i've been testing on, fire can be detected by the phototransistor as far as 12 inches or more!