Hi Guys
ive built a 555 timer as shown in the link below. However i have modified it to have a lower mark space ration than 50% by adding a diode in parallel with R2. It works great and i have the correct mark space ration i calculated for this. However when i add the output transistor on pin 3 my whole signal becomes inverted. Without the output transistor the circuit is fine but as soon as i add it the output becomes inverted. Its high for longer than it is lower.
how can i overcome this problem?
there is no led in my circuit just the collector resistor. Using a scope across output to see waveform.
cheers
andy
https://www.technologystudent.com/elec1/5552.htm
ive built a 555 timer as shown in the link below. However i have modified it to have a lower mark space ration than 50% by adding a diode in parallel with R2. It works great and i have the correct mark space ration i calculated for this. However when i add the output transistor on pin 3 my whole signal becomes inverted. Without the output transistor the circuit is fine but as soon as i add it the output becomes inverted. Its high for longer than it is lower.
how can i overcome this problem?
there is no led in my circuit just the collector resistor. Using a scope across output to see waveform.
cheers
andy
https://www.technologystudent.com/elec1/5552.htm