I have hit a slight problem with this design. Now I have got the inertia control working, I wanted to incorporate the circuit into one of the three LM317K controller circuits in the home made triple controller which was made back in the 90's, by my brother in law.
The idea being the inertia control would be switched in to one of the controller circuits if desired.
I found that with no load the 317K worked well with the circuit, as it should because I believe the TO3 version of the 317 is identical electrically to the small plastic one.
But when a 300mA load was applied the voltage failed to rise beyond about 2.6v.
After treble checking everything, and being baffled, I removed the protection diode D1 and found the circuit worked fine.
I then had the thought, smoothing capacitors were never fitted to this controller when it was made. Possibly because they are not shown on the application circuit, or also possibly because he wanted to not smooth the rectified 15v DC save the voltage rose too high.
Anyway fitting a 2200uF capacitor to the rectified DC has cured the problem of the inertia controller not working and has allowed the D1 protection diode to be refitted. But it has also resulted in excessive heat in the 317K regulators which were not fitted with any heat sink at the time.
The only solution is a complete dismantling of the printed circuit, (which is a bit like a prototype breadboard) and redesigning the layout to incorporate heat sinks.
However with the extra smoothed input voltage the regulation is now better under load than it was before in its original design with just the 15v input into the regulators.
Mike
The idea being the inertia control would be switched in to one of the controller circuits if desired.
I found that with no load the 317K worked well with the circuit, as it should because I believe the TO3 version of the 317 is identical electrically to the small plastic one.
But when a 300mA load was applied the voltage failed to rise beyond about 2.6v.
After treble checking everything, and being baffled, I removed the protection diode D1 and found the circuit worked fine.
I then had the thought, smoothing capacitors were never fitted to this controller when it was made. Possibly because they are not shown on the application circuit, or also possibly because he wanted to not smooth the rectified 15v DC save the voltage rose too high.
Anyway fitting a 2200uF capacitor to the rectified DC has cured the problem of the inertia controller not working and has allowed the D1 protection diode to be refitted. But it has also resulted in excessive heat in the 317K regulators which were not fitted with any heat sink at the time.
The only solution is a complete dismantling of the printed circuit, (which is a bit like a prototype breadboard) and redesigning the layout to incorporate heat sinks.
However with the extra smoothed input voltage the regulation is now better under load than it was before in its original design with just the 15v input into the regulators.
Mike
