Self accelerating reed switch magnet spinner.

[TinselKoala]

Hey, I'm no stranger to Arduinos, you know!

[MileHigh]

TK:

Need some new project ideas?

http://www.youtube.com/watch?v=VlOxlSOr3_M

[TinselKoala]

Grrl need to lay off them triple spresso shots and stick to decaf lattes for a while.

[MileHigh]

TK:

I was racking my brain trying to think of what could be interesting and different to add to the mix as a deluxe bonus at the end of this endeavour.  So I finally came up with the following:

Let's look at some initial conditions:

If anybody is going to buy op-amps from DigiKey they are so cheap that chances are they are going to buy somewhere between 10 and 25 pieces.  Note the TL082 is a dual op-amp so that's a lot of op-amps.  Most experimenters probably have at least two or more cheapie digital multimeters.  Most pulse motor experimenters will probably have an optical tachometer.   Most experimenters will probably have a bunch of 9-volt batteries laying around.  Most pulse motors probably consume 10 watts or less of input power and output four watts or less into a charging battery.  An operational amplifier is a device that can perform mathematical operations on voltages like additions, subtractions and multiplications.

So, put that all into a blender and what do you get?  A word salad?  Nope, this is a magical "negative entropy" blender.

The goal would be to convert your cheapo multimeters into real-time watt meters using a few of the operational amplifiers at your disposal.  This is doable within certain constraints that are met by pulse motors.

So you can think of a scene like this:  As you tweak your MileHigh pulse motor playing with the pulse duty cycle (a.k.a. dwell angle or conduction angle) and adjusting the pulse start time (or you could call it the pulse start angle) relative to TDC with your moveable sense coil,  one multimeter is displaying the input power in watts in real time and another multimeter is displaying the output power in watts in real time.  So you monitor your live input and output power levels while you spot check your RPM with your optical tach while you tweak away.  I figure that might be exciting stuff for an avid pulse motor builder.

Note this will work with any kind of pulse motor, so it's a useable concept that can be applied to all sorts of other builds.

Anyway, I know you did a rebuild and you stated you will be doing some new clips and all that.  Then you may find yourself doing other things.  So perhaps this idea could be fleshed out when you are done.  You might be tempted to build it yourself or at least it can be discussed in enough detail so that a determined pulse motor builder could bootstrap him or herself and do the circuit to convert their cheapo multimeters into watt meters.

MileHigh

[conradelektro]

The goal would be to convert your cheapo multimeters into real-time watt meters using a few of the operational amplifiers at your disposal.  This is doable within certain constraints that are met by pulse motors.

So you can think of a scene like this:  As you tweak your MileHigh pulse motor playing with the pulse duty cycle (a.k.a. dwell angle or conduction angle) and adjusting the pulse start time (or you could call it the pulse start angle) relative to TDC with your moveable sense coil,  one multimeter is displaying the input power in watts in real time and another multimeter is displaying the output power in watts in real time.  So you monitor your live input and output power levels while you spot check your RPM with your optical tach while you tweak away.  I figure that might be exciting stuff for an avid pulse motor builder.

Note this will work with any kind of pulse motor, so it's a useable concept that can be applied to all sorts of other builds.

MileHigh

Measuring input power with operational amplifiers: the circuit has to be calibrated, which needs at least a good Voltmeter. The input power is fed as pulses, which are difficult to measure without a scope (integration of the Voltage curve over a shunt).

Measuring output of a pulse motor: this should be the mechanical output (torque) which needs some sort of Prony Brake http://en.wikipedia.org/wiki/De_Prony_brake and good scales. To build good scales with operational amplifiers is a major task. The Prony brake looks easy but is mechanically tricky (the braking belt or braking clamp heats up fast).

http://en.wikipedia.org/wiki/Torque_sensor would need a torque sensor.

How are the measurements displayed?

The reason why we see hardly any consistent measurements from pulse motor experimenters is the difficulty of good measurements.

Greetings, Conrad