Luke James

1 week ago | forum.allaboutcircuits.com | Luke James

I have an on demand water pump that is controlled via a simple push button switch which momentarily shorts a 12V circuit to activate the pump for a set period of time. I want to replace this switch with something to do the same job, via an RF remote. I have looked at the various relays online. e.g. this one,https://www.amazon.com/Switch-Wirel...ansmitters/dp/B071WM1YGS?ref_=ast_sto_dp&th=1but I can't figure out how to wire it for this situation, or even if it could work at all.

1 week ago | forum.allaboutcircuits.com | Luke James

I have some of these:The one my desktop PC is connected to shows that red switch flickering, like it has a neon or something inside it. Another one is on and devices are all powered fine, but the red switch is not illuminated at all, it is dark and cycling the switch has no effect, it remains unilluminated. Is there anything to this? the one that has flicker, is that a fault? could it cause noise or something on the power coming out?

1 week ago | allaboutcircuits.com | Luke James

Medical diagnostics are shifting fast, from bulky, hospital-based equipment to compact, intelligent devices that operate in real-time and closer to the point of care. In this article, we look at three recent prototypes: a dissolvable pacemaker powered by light, a handheld AI-driven heart sound recorder, and a bioinspired sensor platform that tracks hundreds of metabolites in the body. Engineers at Northwestern University have built a new pacemaker small enough to be injected through a syringe.

1 week ago | forum.allaboutcircuits.com | Luke James

Hi gang, I've got a Pioneer AVH Z2050BT head unit, CD/DVD, Bluetooth, FM inputs all work, audio output to speakers functioning. The USB port on the back rated at 1.5A 5V is not outputting any power or receiving any data to output Apple CarPlay onto the display. Phone not recognizing anything is connected to it either. Have tried several cables and also made sure the phone itself outputs CarPlay on other units. Narrowed the issue down to the USB port/circuit on the unit itself.

1 week ago | forum.allaboutcircuits.com | Luke James

I'm trying to build a 3-stage BJT amplifier to amplify the signal from an electret microphone and drive a 3W, 8Ω speaker. I'm kinda stuck and need some help. My idea is to use the first two stages as common-base amplifiers, each with a gain of around 15.5. The mic outputs about 20 mV, and I calculated that the speaker needs around 4.9 V peak to deliver 3W, so I aimed for a total gain of about 240. The third stage is a common collector to help drive the speaker.