The circuit is just a flasher operating at 40 kHz which is the carrier frequency used by common remote controls. The strong 40 kHz infrared flashing interferes with the signal from the remote.
The 50k potentiometer is adjusted to achieve a 40 kHz flash rate (around 20 kohms) and this adjustment is fairly critical. When it is set properly and the LEDs are pointed directly at the receiver's photodiode, the remote control will stop working. The LEDs are operating at about 30 mA when on but the duty cycle is low and the circuit only draws about 7 mA.
Trouble may be encountered if the frequency is set wrong, the LEDs are not pointed correctly, or if the remote is a real brute. More light may be had by adding another resistor and diode string from the collector to the switch but the most likely problem is the frequency adjustment. Use a 10-turn pot and adjust it slowly while changing channels. Or use a frequency counter or oscilloscope to set the frequency, if possible. Make sure that the current drain is about 7 mA - if not, check the polarity of the diodes. A photodiode infrared recaeiver is handy for checking the light output and comparing it to the remote's.
The 50k potentiometer is adjusted to achieve a 40 kHz flash rate (around 20 kohms) and this adjustment is fairly critical. When it is set properly and the LEDs are pointed directly at the receiver's photodiode, the remote control will stop working. The LEDs are operating at about 30 mA when on but the duty cycle is low and the circuit only draws about 7 mA.
