Sounds like you got what yor wanted. If you askd for a "transmit" and "receiver" diode.
Better to list the part numbers here to be sure. Someone here can find out or knows off hand. But you can search google on you own and get the spec sheets to detemine the use and wiring. the transmit LED should look like a regular color one, just clear or black. The reviever could have a flat face or slighly rounded but looks diffrent.

what is your project?

Why not ask the dealer who sold you?

teh transmitter led is usually as same a s ordinary led at outline but reviever look like a square plate.

the first reply above is right.

Hi I use Infrared Led / Infrared Detectors a lot though not necessarily for remote control units.

Infrared LED s used in most of the remotes are of 5mm diameter and generally the colour of lens /body is crystal clear or comes with a bluish tinge and sometimes black.

The DETECTOR too comes in 5mm diameter ( also comes in black flat pack and has three terminals,in fact it has an amplifier built in)and the colours are crystal clear, or black, in some applications (as in my case )black colour helps in reducing the ambient light interference.

a detector can be easily identified with the help of a analogue multimeter connected to the two leads of a detector and focussing /blocking an incandescent lamp, and observing the swing of the resistance value.

hope this helps

thanks

pkd.

I think I understand your question differently than posters 1&2, but hopefully can help.

The sending device (which is what I assume you are referring to as the Transmission Section) must emit IR and is therefore an IR LED (or two).

In my experience both photo diodes and photo transistors are receiving devices, with the older photo diodes having mostly been replaced by the more sensitive photo transistors.

Open the case on any TV remote control, and sticking out of one end of the circuit board you will see an IR LED. As the others said, it looks just like any other LED except that it will be clear, red, or dark to nearly black in color, not green, etc. The few remotes I have taken apart used through-the hole lead mounted LEDs, but I wouldn't be surprised to see surface mount devices in newer remotes.

Measuring with a multimeter set to the diode scale, in one polarity the meter should not change, while in the other polarity an IR LED should indicate about 1 Volt. For visible LEDs, the voltage will indicate much higher, around 1.7 V for red, and higher still for yellow, green, blue. These values will change very little, if at all, when moving the device into or out of a bright incandescent light source.

Do the same with a photodiode or phototransistor; again in one polarity the meter should not change, but in the other polarity The reading will vary greatly when moving the device into or out of a bright incandescent light source, dropping to as low as 0.05 Volts or less when in the light. Some phototransistors have 3 leads, so you might have to experiment to find the right pair. Phototransistors will change more rapidly, and react to dimmer light than photodiodes. Note that fluorescent lights put out very little IR, so you must use incandescent for a good test.

In summary, you were right to question the information given by 'the shop'.

the circuit which i have selected is Remote Switch

By using the remote i will press a push button switch, by using IR led it will be transmitted and received by reciever then relay operates the load

i picked this circuit from Electronics For You magzine