Hello,
I am quite new to electronics and I am facing a problem with my circuit. The aim of this project is to have a PIC generating a square wave (100 us ON; 100 us OFF) that will drive a BC548. Since the output voltage of PIC is 5 V, the BC548 is used to have the same square wave but with higher voltage. To achieve that the "Variable DC Source" feeds the circuit with 24 V. I was expecting to have a square wave with variable voltage as I change the "Variable DC Source". However, everything goes well until 8.6 V. Then, the square wave shifts up (as I increase the voltage) instead of reaching a higher voltage. There is a offset of the whole square wave.
Find attached 3 figures:
- The circuit;
- One photo of the oscilloscope when the "Variable DC Source" was feeding the circuit with 8.6 V;
- One photo of the oscilloscope when the "Variable DC Source" was feeding the circuit with 14 V (the square wave is shifted up).
How can I change my circuit in order to have what I need: a Square Wave paced by the PIC with a variable voltage?
Thanks.
Dan07.
I am quite new to electronics and I am facing a problem with my circuit. The aim of this project is to have a PIC generating a square wave (100 us ON; 100 us OFF) that will drive a BC548. Since the output voltage of PIC is 5 V, the BC548 is used to have the same square wave but with higher voltage. To achieve that the "Variable DC Source" feeds the circuit with 24 V. I was expecting to have a square wave with variable voltage as I change the "Variable DC Source". However, everything goes well until 8.6 V. Then, the square wave shifts up (as I increase the voltage) instead of reaching a higher voltage. There is a offset of the whole square wave.
Find attached 3 figures:
- The circuit;
- One photo of the oscilloscope when the "Variable DC Source" was feeding the circuit with 8.6 V;
- One photo of the oscilloscope when the "Variable DC Source" was feeding the circuit with 14 V (the square wave is shifted up).
How can I change my circuit in order to have what I need: a Square Wave paced by the PIC with a variable voltage?
Thanks.
Dan07.
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