Big Motor Driver TLP250

I have posted a motor controller design that is supposed to be simple, robust, cost effective, and able to handle high currents.  Above is a schematic of the first part of the design.  I will post an updated version to include a PIC to accept commands from a PC, Microcontroller, etc. and provide the direction/PWM signals to the H-bridge.  I am still working on the PCB but here is what I have done so far for review/critism.  What is not shown in the schematic are the in-line fuses for protection.

For the PIC, I use MBasic and PicBasic Pro to write the code.  This should convert easly to the BS2 and PicAxe.


 I updated the schematic again.  As suggested I changed the MOSFET driver to a TLP250 and dropped the 1K resistor across the Gate to source.
Update the schematic to show that the logic grounds are isolated from the dirty motor grounds.

Finished the PCB design.  Once boards are complete will test and post schematic and board files once any kinks are worked out.

I got the prototype boards back from the manufacture two days after I sent them off.  As you'll see below, the quality is excellent.  Tonight I populated the board and checked out functionality with a multimeter prior to testing with a motor.  I managed to get everything put together right so on to the smoke check.  I hooked up a good size motor with a lot of torque and applied power.  The motor moved in both directions and the MOSFET did not even get warm.  This test was applying full power to the motor and not PWM.  Next, I'll write some code and test functionality with PWM hooked to my Oscope so I can check the signals and see how high I can take the frequency.  I'll get around to posting some video but, in the mean time, here are some pictures of one of the finished boards.

Metal sensor detector circuit schematic TDA2822

The metal detector circuit is shown here that the limits represent the sake of simplicity for a metal detector, but the design works remarkably well. It only uses 40,106 Hex Schmitt inverter IC, a capacitor and a search coil – and of course batteries. An advantage of IC1b Pin 4 is to be connected to a medium-wave radio antenna, or it should be wrapped around the radio. It can also be used as a hand-held metal detectors. As you can see what metal a good selection of beat-frequency operation (BFO), up to 90 mm for a bottle-top. In fact, for the ultimate in simplicity, the capacitor C1 is omitted. In this way, the author reaches is astonishing, 150mm range for the bottle top. But with the frequency then to more than 4 MHz, the instability is a major problem. TDA2822

 

As shown in the circuit, oscillates at 230kHz. You can also experiment with the frequency by changing the value of C1. Faraday shield can be added to reduce ground-effect and capacitive coupling, and this is connected to 0V.
Since the inductance is resistance to rapid change in voltage, the charging of fees C1 delayed a bit like the logical level IC1a 2-pole change. This requires a rapid oscillations, which is repealed by an AM radio. Any change in the inductance in the search coil (by the presence of metal) to a change in the oscillator frequency. Although 230kHz is out of reach for the medium-wave band, an AM radio will significantly increase this frequency harmonics.
Metal detector calibration
This makes the search coil L1 is much room for error and is not far from conclusive. The author uses seventy turns 30 s.w.g. (0,315 mm) copper wire on a former 120mm diameter.
The metal detector, set up by the AM radio to pick up a whistle. Not all of these harmonic functions well, and are best suited to. The presence of metal will significantly change the sound of the whistle.

* Metal Detector FAQ *
This is not an industry or security metal detector and is not even near loma or ERIEZ metal detection system. It’s just a notebook, but not hand-metal detector.