- #What is actually inside a fake 2n3055 transistor series#
- #What is actually inside a fake 2n3055 transistor tv#
and input delay by R3, C2 set about 1.5 seconds. The output pulse is set at about 2.4 seconds. Note that quick turn on and off of the relay is not possible. For every pulse the relay will operate and latch, the next pulse will turn off the relay and so on. The input is applied to the clock pin, the inverted output fed back to the data input and clear and preset lines are tied to ground. Any version of the 7474 may be used, i.e.
#What is actually inside a fake 2n3055 transistor series#
This is a D type flip flop, built with a TTL 7474 series IC and configured as a bistable. A clean output pulse is produced to activate the bistable latch, IC4. This is achieved using a 555 timer wired as a monostable, IC3, having an output pulse duration R5, C4. These edges are produced by the modulated IR data, and have to be removed. The pulses are further buffered and contain "jaggered edges" as shown above. Note that this is not from the actual circuit ( in which case the reconstructed pulse would be high for the duration of the 555 monostable) but only a spice simulation. A simulation of received pulses, filtering and output pulse is shown below. Once reached the inventor triggers the 555 timer and operates the flip flop. As the power supply is 5 Volts, the input threshold is around 3.6V, which takes about 3RC's or about 1.5 seconds. In this circuit the capacitor charge has to reach the logic threshold of the CMOS invertor. It takes 5 RC's for a capacitor to reach 99% charge. At one RC a capacitor will only charge to 63% of the supply voltage. The time taken to charge a capacitor is the product of resistance and capacitance, more commonly known as the RC time constant. If using a TSOP1738 then increase R4 to 470k. C2 charges via R3, and discharges via R4, D1 prevents quick discharge via the low output impedance of the CMOS buffer. Another gate buffers the signal and applies it to the time constant circuit, comprising R3,C2,R4 and D1. One gate of a CMOS inverter drives LED1 as a visible switching aid. A replacement for IR1 is the common TSOP1738 IR reciver. It has a standard TTL output, the output with no signal is held high by R1. IR modulated pulses are received and buffered by this IC. You can connect anything to the relay, for example a lamp, but make sure that the relay contacts can handle the rated voltage and current. In order not to change channel, you could press the button of the channel you are watching.
#What is actually inside a fake 2n3055 transistor tv#
To reset, any button is pressed on the remote handset and held for a short duration.įor example, if you were watching TV, you could press and hold any button on the TV remote to trigger the circuit. The circuit will remain in this state (latched) until reset. The button must be pressed for about one and a half seconds (determined by R3 and C2) before the relay will operate. Board, Sockets For ICs, Knob For R6, Battery HolderĪny "button" of any remote control may be used to work this universal switch.