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Circuit to reverse polarity not working

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audioguru:

This is similar to the circuit i was talking about. You'll have to find better values for the base resistors of course but we'll save four transistors this way.
Power transistors are spec'd for a fair saturation voltage loss of about 0.5V when their base current is 1/10th the collector current. The OP wants the circuit to work with 1A loads so the 2N390x driver transistor will need to conduct a whopping 100mA. The its base current will need tro be 10mA for it to saturate as per spec so the input to it needs is 10mA which many ICs (Cmos) cannot produce.
 
I have a dumb question about what the O/P is trying to do. No one else has asked this so here goes. What are you trying to do by reversing the polarity direction through the solenoid? The solenoid doesn't care which way polarity flows through it, it is just an electromagnet. It won't change the way the plunger moves by reversing the polarity.

Or by solenoid are you meaning an inductor?
 
I have a dumb question about what the O/P is trying to do. No one else has asked this so here goes. What are you trying to do by reversing the polarity direction through the solenoid? The solenoid doesn't care which way polarity flows through it, it is just an electromagnet. It won't change the way the plunger moves by reversing the polarity.

Or by solenoid are you meaning an inductor?

I looked up the word inductor. I cannot answer you as I don't fully grasp what Wikipedia tells me. My "solenoid" is a coil without a core, in fact, it has a 19mm hole through it and is wound on a copper spool to prevent the other component, a magnet, from interacting when the solenoid? is not active.

I suppose trying to be brief lacks clarity :) So here goes..... As a hobby I repair steeple clocks (turret clocks) (church clocks). You may want to look at Repair of public building clocks. New electronic and digital clocks. to see what it entails. Timekeeping for these old mechanical machines built a hundred plus years ago is mostly a challenge. Also a challenge to the clock custodian who has to make sure the clock is on time. Staircases are precarious to say the least. I have the honour of looking after our local church clock and after a couple of years, going up the tower is getting too much, so after looking what is available commercially, I decided that I can do a better and less costly system to keep the clock on time. My PreciTime V1.00 has been running successfully for a while now, so it was time to improve and update. Where the old version had physical contact with the pendulum, the new version uses a solenoid plus a magnet to ever so gently control the position of the pendulum. So there you have it, the solenoid must be able to push and pull because it is unpredictable if today the clock will be fast or slow. That depends on the temperature and the air pressure, amongst other things.

The system uses the signals of the GPS satellites as a time base, so the clock is always on time to the last fraction of a second.

It would have been more simple to put two relays in there, but they are mechanical devises and the current version of PreciTime boast "no moving parts", so it is maintenance free.

Now may I mention that electronics is a new experience for me and the learning curve was steep, but with the help of people like you on the news groups I have learnt a lot and loving it. Thanks to you all for your help.

I suppose trying to be brief lacks clarity :) So here goes..... As a hobby I repair steeple clocks (turret clocks) (church clocks). Timekeeping for these old mechanical machines built a hundred plus years ago is mostly a challenge. Also a challenge to the clock custodian who has to make sure the clock is on time. Staircases are precarious
 
OK, that makes sense. The plunger is a magnet instead of a iron rod. Kind of a linear motor then.
Thank you for the clarification.
 
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