Good day all, I'm looking for an expert advice on a solenoid project and the parts required in order to use it safely. [B]Project description:[/B] 2 push-pull solenoids have to be activated instantaneously by a left mouse click. The same left mouse click will also trigger an action in a program on a pc such as a sound and a visual effect. The software part is already built and ready to use. [B]Parts already owned:[/B] 1- 2x [URL="https://www.amazon.ca/uxcell-RM-1564B-DC12V-Solenoid-Electromagnet/dp/B016MMWCR8"]12VDC 2.5amp solenoids[/URL] 2- 1x 12VDC power supply 450 watts 3- 1x solderless diy breadboard and accessories 4- Mouse with a wire attached to left mouse button for solenoid activation 5- PC [B]Parts that need to be acquired[/B] 1- 2 NPN transistors or relays to close from a mouse the solenoids DC circuit 2- 2 diodes to protect circuitry from solenoids potential emf return [B]Schematic[/B] See picture attached [B]What I need to know[/B] Many people recommended the use of NPN transistors such as Darlington TIP120 with an added heatsink since these chips can handle high current, they are fast and reliable. Other recommended relays since they can handle higher current but they are slower and more subject to wear over time. My main requirement is to have an instantaneous reaction from the solenoids when the left mouse button is pressed so they are in perfect sync with the pc program. My main concern is that all the examples I've seen were showing lower-power solenoids with NPN transistors. At 2.5 amp each, the force of my solenoids is quite high and I want to make sure that the transistors can handle that power without frying. An other major concern is that I want to make sure that the 12VDC current from the power supply cannot find a way back to my pc through the 5V USB circuit. Should I place a diode on the USB circuit as well to limit the flow to one direction? Any recommendation from the community would be appreciated. Thank you!

I've got a Noritz NR98SV tankless unit and the hot water will sometimes go cold in the middle of a shower. No error codes have ever been thrown and I've got a water softener and have also flushed it regularly. I took a look at what was happening and found that the water goes cold because the whole unit turns off and then turns back on about a minute later. When the the unit turns off, the power from the receptacle is out. The circuit breaker does not trip. And then soon after, power from the receptacle is back and the unit turns on. I replaced the receptacle but the problem continues. Any ideas?