#ON OFF SWITCH POWER SUPPLY HOW TO#

Is there any need of dielectric isolation between the input and the output?.

What is the range of the output voltage as compared to the input voltage?.The following features must be kept in mind while choosing a topology: In order to select the most suited topology, the complexity, drawbacks, basic operation, advantages and area of usage should be known. SMPS has different topologies in it where there are different specifications and features of every topology. SMPS have many applications in power electronics projects. But their simpler designs can have a poor power factor, noise problems and they are also more complicated. The switching regulators are mostly used where we require highly efficient and smaller regulators. Application based project using SMPS Switch Mode Power Supply.comparison between linear and switch mode power supplies.WORKING OF THE DIFFERENT SMPS TOPOLOGIES.With the relay active, it close the circuit of the Live wire, taking over to supply the Power Supply. M80 force the PS_ON line to 0V/GND causing a voltage over relay, thus enabling it.Duet starts up, and runs the config.g file, which should contain M80.With the switch pressed, power supply starts up, gives 24V to Duet and Relay Module (note that at this time, PS_ON is in high-impedance, thus it lifts to 24V).

This allows either to allow power through (switch is meant as Bypass, so when printer is on, it have no effect). Both the switch and the relay is between the IEC Mains input and the Power Supply on the Live wire.Also note that the relay module needs the fly-back diode for protection (if you implement your own relay, make sure the diode is in place). The relay shown is rated at 5V, however I recommend a 24V (otherwise you will need to step the voltage from the power supply down). I have quickly created the image below showing the relevant wiring. Note that the firmware does not currently use the PS_ON for safety etc, but it may be implemented in the future (where the printer can shut itself down if a thermal runaway was detected). In my configuration, I only need to press the button for less than a second, and the printer is on. If you select Ok, M81 is run, which release the relay, and the printer is off. The first line asks if you are sure to shut it down (while having the axis jog buttons on screen - useful to move the head, if you need to move it before shutting down), with a Cancel button that simply exists. The idea is very simple: macros can be triggered by accident, and shutting down mid print is bad. Note that the M80 command should be in your config, as otherwise the relay will not engage (when I upgraded to RRF3, I forgot about that - had to keep the switch pressed while sending M80, before I could edit the config).Īs to the Macro, here is what I use to turn the printer off: M291 P'Turn printer off? Move axis now or cancel.' R'Shutdown Printer?' S3 X1 Y1 Z1 Further you wire everything like normal.The Relay's Ground should run to the Duet's PS_ON pin (when this pin is enabled in software, it will become Ground potential, thus the relay is enabled).a +24V wire should then go to the Relay's signal/coil side (some of these modules have a Positive, Signal and Ground terminal in this case, get 24V to both Positive and Signal).The idea of this nr 2 is to provide a Relay and a Bypass line for the power (bypass allows the power supply to power on, supplying power to the Duet which in turn will enable and keep the Relay enabled).The second wire goes to the switch, with once again a wire from the switch to the Power Supply live input. The first wire goes to the Common on the Relay and a wire goes from the Normally Open on the Relay to the live input on the Power Supply.Ģ.2. From the IEC plug, the live wire splits into 2:Ģ.1.On my printer I had an IEC (computer power cable) plug, with fuse and switch (this is how the power enters the printer, and this switch is also the master switch).1 Momentary Switch (this should also be mains rated, and at least 2A - the printer will startup through this switch).1 Relay (I used a relay module, that is rated at 24V for the signal, and 10A Mains for the switching side).My own setup is similar to what you describe:

#ON OFF SWITCH POWER SUPPLY HOW TO#

Some other power supplies have a remote function to turn it on or off, if yours have it, read the manual on how to use it.

On off switch power supply