This isn't directly connected to picaxe, but thought that some here would be interested.
I have just purchased a white LED strip with dimmer. I don't need the housing on the dimmer and while removing it thought I would take a closer look at the circuit.
It wasn't long before I started to get quite intrigued by how the 555 was being used in combination with an op-amp in comparator setup.
the higher the voltage going into the non inverting input the higher the duty cycle.
The traces show the saw tooth signal from pin2 on the 555, while the other trace shows the signal coming out of the op-amp.
Please note the MOSFET shown in the schematic isn't the one the circuit, just a stand in from what I had in my eagle library. The actual component is 090N03L, which appears to be a power MOSFET.
I have just purchased a white LED strip with dimmer. I don't need the housing on the dimmer and while removing it thought I would take a closer look at the circuit.
It wasn't long before I started to get quite intrigued by how the 555 was being used in combination with an op-amp in comparator setup.
the higher the voltage going into the non inverting input the higher the duty cycle.
The traces show the saw tooth signal from pin2 on the 555, while the other trace shows the signal coming out of the op-amp.
Please note the MOSFET shown in the schematic isn't the one the circuit, just a stand in from what I had in my eagle library. The actual component is 090N03L, which appears to be a power MOSFET.
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