Magswitch Technology MAGJIG95 On/Off Magnetic with 95 lb/43 kg of Vertical Holding Force Yellow

Product Information

Don’t heat up Magswitch ® magnets. Like all neodymium magnets, high temperatures can partially demagnetize them. Avoid anything above 176°F (80°C). R10 needs to be a power resistor. When you insert 100mΩ of resistance into the input... Read more » A perfect entré into the Magswitch Workholding System. Once you have this tool, get all the other great tool attachments and simply mount them to the base as needed. There may be some users that want to locate the hall-effect sensor away from the main circuit board. I added pads to allow leads to be soldered instead of mounting the sensor on the board.

Power to the load can be switched on or off by momentarily placing a magnet near the circuit. This allows the circuit to be completely enclosed within the aircraft fuselage.The current drawn from the batteries while in the off-state mode should be as low as possible. It should take more than one year to discharge the battery.The voltage drop across the switches should be as low as possible to keep power dissipation, heat, and losses to a minimum.I soldered two 30AWG Kelvin leads to the PCB pads near where the wires were connected. The location of the Kelvin leads makes a big difference in the measured voltage drop across the FETs. Since I don't have any precision/programmable load that can generate 40A I used my Tundra airplane's motor and ESC to provide the load. The Tundra draws very close to 40A during full throttle from a near fully charged hefty (5Ah) 3S LiPo battery. Now, the cool part about a Magswitch ® is that you can turn it OFF. Here’s where the magic happens. When you rotate the knob, you’re rotating the top diametrically magnetized disc magnet by 180°. Now the magnetic field flows from one magnet, through the steel wall and into the other magnet. Replaceable pole shoes, cut maintenance cost and allow for Taylor made pole shoes to be fitted for repetitively lifted irregular shapes parts such as pipe. This all looked pretty good. I decided to see what the input transient voltage waveform looked like for a couple of different battery types:

The folks at Magswitch ® must have done their math right, because the steel structure is shaped and sized just right to keep all of the magnetic field flowing inside the assembly. It doesn’t reach outside at all! In this position, no pull force is felt. With load current 35A, the voltage across the switch was 40mV (that's 1.1mΩ). Power dissipation is only 1.3W, which should not be a problem for a board even this small. I repeated the measurement with 20A load current and got 22mV across the switch, and the same switch resistance. No changes required. So here's the plan: I assembled one of the second pass 30A prototypes using different FET switches than the first pass -- substituting a Vishay SiSS28DN for the IRLHM620. The Vishay part claimed slightly lower RDSon (1.6mΩ vs. 1.8mΩ @ VGS = 4.5V) and a higher max VDS of 25V instead of 20V. I thought, erroneously, that the higher voltage rating might improve the survivability of input transients when batteries are plugged into the input. The addition of R1 between the input and the LDO solves the problem by eliminating the capacitor (C2) that caused the ringing so a higher voltage rated FET is not required to support 2S-4S LiPo batteries.

Not much is different. The change is to the FETs and how they are driven. Previous magnetic switches were driven with 5V gate voltage. This circuit level shifts the gate voltage of the output switching FETs to 12V to extract every bit of RDSon that the FET is capable of providing. The Magswitch magnetic fixturing clamp will secure your fixture into place. Rotate the knob to turn on and off 95 pounds of magnetic hold force. Simply drill a hole in a fixture and place the MagJig in to use for downward pressure clamping. FEATURES & BENEFITS I've tried the low current LEDs, but the one I used previously wasn't very bright. Plus I have an inventory of 0603 LEDs in a bunch of colors that cost me a penny/each. They seem plenty bright to me at 5mA -- the request that I got was to make the LED visible in bright sunlight while out at the flying field. Compared to the 4A or 30A load the 3mA of LED current is a nit. The example shown uses two RC4CDIA, diametrically magnetized ring magnets. We chose ring magnets instead of cylinders because they were easier to mount using off-the-shelf hardware. We put them side-by-side to make it easier to build and see.

Magnets can be positioned at different points on the fence for optimal placement on drill press tables.At Magswitch, we strive to ensure every Magswitch tool makes the work place safer, improves productivity, is maintenance free, reduces energy consumption, is easy to use and has an ROI measured in weeks or months. In short, a Magswitch tool is designed to exceed customer expectations!

Voltage drop across FETs during 40A load: 13.5mV. That's 0.34mΩ switch resistance. With a 40A load the switch will only dissipate about 0.54W. It should be able to handle this load continuously without overheating. Edit 2020-02-02: BHarbour pointed out my laziness in his comment. The following is a bit of extra work to solidify the design.] Reducing the standby current: With up to 1,100 pounds of hold force, on thin material, important when used in barge and tank building. Productivity and Cost to Deliver Designed to work on any cast-iron table to hold down your work so you don’t have to. It works on both sides of the blade and even the fence. It features two 20mm Magswitch MagJig 95 magnets. Guides Dual Roller Guide The switch no longer is sensitive to disconnection by high currents. I ran more than 35A through it and it remained closed.Electromagnetic and vacuum lifting systems are costly in the long term regarding energy and maintenance costs. Magswitch ‘Greentech’ technology will offer you significant savings in energy and repairs while increasing productivity. Custom Solutions NO drop zone risk. By using the MagReach 400 accessory the operator can control the load, under hook, from a safe distance, without entering the drop zone, increasing safety and reducing operator stress and the safety of those in the work environment. The Magswitch Magreach 400 allows the operator to stay clear of the fall and climb zones. What is the Pareto Factor, when using a Magswitch CE Lifter? Our products are designed to be ‘fail safe’ since there is no need for any power during a lift. With a positive indication of the magnetic circuit, the operator can confidently perform knowing the material is fully attached. Magswitch offers Electric, Pneumatic, or Manual for ‘on-off’ actuation. Performance My first thoughts were to add a snubber -- a series R and C across the inputs. This could be just a tantalum capacitor with an appropriate ESR value . The problem I found was that the capacitor had to be greater than 100µF and the series resistance (or ESR) around 100mΩ. I could not find a reasonable size ceramic 100µF capacitor with a 25-50V rating, or a tantalum with <500mΩ ESR. The solution for the snubber to work was to put 15x 10µF ceramic caps in parallel -- so I abandoned this idea in favor of adding resistance in series with the input. The switch should dissipate a maximum of 0.6W for an applied current of 40A. Maximum current can exceed 1000A for short durations ( less than 100µs). That should be adequate.