I have made a daynight switch for my LED solar lights and have been switching a relay through a BC547 transistor.
I have included a time delay by doing the following
From the output (pin 6) through a 30K resistor a 470μF capacitor is charged. A 100K resistor feeds the base of a BC547 which turns on a 12 Volt relay.
For the sake of Space I want to take out the 12Volt relay and substitute it for a TIP41.
My question is will i be able to substitute the BC547 with the TIP41 ( Naturally observing the pin spacings are not the same) Or will I have to have the BC547 to turn on the TIP41.
A 741 opamp is 45 years old. It was designed to use only a 30V supply and work at DC and low frequencies. It is noisy.
There are thousands of much newer and better opamps available almost anywhere.
But we do not know where you are.
I will post the diagram a little later, I am based in Zimbabwe, we have 3 electronic shops which carry reasonable stock, failing that I import what I need from South Africa from RS Components, Mantech Electronics and Communica. I have a friend in England who sends me things from Maplin when I need and I sometimes purchase from China.