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Return to BlogPulsating LED with Fading IN/OUT Effect
Posted Feb 09, 2012 at 12:00 pm
Figure 1
The design illustrates the fading and brightening of the pulsating LED with the use LM1458 op-amp functionality.
The LEDs are made to fade or illuminate depending on the output voltage in the range between 2 to 7 Volts, although a fixed voltage of 9 V is basically taken by the LM1458 op-amp. The operation of LM1458 to reverse the values of voltages is dictated by the action of 2N3904 that runs as a voltage comparator.
The circuit was built in a small piece of veroboard and uses a double-sided tape to stick the board inside the case. Most of the components of the circuit are very sensitive to heat, especially the op-amps, when soldering is being applied. During soldering of wires, the iron on their pins should not be hold for any long period of time in order to avoid the component to be damaged after doing the soldering process.
The board is mounted in the case where an extra PSU connector is hooked up. For the possibility of easily changing the output LEDs, a regular motherboard LED connector is added to the circuit. The LED colors could be blue or green.
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2 years ago: The circuit looks like jammed! maybe rewiring and reconnecting them would make this design like nicer :)