If you modulate the IR LED with 1A pulses then the transistor driving it conducts 1A through it and 1A comes from the bypass capacitor across the supply.panadol said:hhmm..ok..but how high will the current be?
You are sending continuous pulses without pauses, so the TSOP thinks it is interference and it turns down the gain. Read again what I said about sending bursts of pulses:i am just sending a square wave which is tuned to 38khz, its that consider burst of pulses?
"The TSOP seres of IR receiver ICs are designed for remote control of TVs and other entertainment products. Data is sent in bursts of IR pulses and the automatic gain control in the receiver IC uses the breaks between bursts to know it is data and is not continuous interference. If it receives continuous pulses then it reduces its gain, thinking that the continuous pulses are interference from a compact fluorescent bulb or other item that continuously pulses IR at 38kHz.
The data burst consists of a start bit, the command code bits (volume up or down, channel number etc) then a device code (TV, DVD player, CD player etc). Then a pause between that burst of pulses before the burst of pulses is repeated again if the button is still held down.
The TSOP receivers have an automatic gain control that reduces the gain during a continuous signal, because it thinks it is interference. Therefore the data must be received in bursts of from 10 to 140 data pulses then a gap time of at least 14 pulses between bursts for its gain to continue at max."
You can buy them with a narrow beam or a wide beam or anything in between. They use a medium wide beam.i am curious how remote control are tuned. The IR emitter in remote control are just ordinary ones, but how they made it that it can be sense at all directions even not pointing directly to the tv?(if im not wrong, IR in remote contorl is narrowbeam...)