App note: Analog switch lowers relay power consumption

Clever way of starting-up relays discussed in this app note from Maxim Integrated. Link here Relays are often used as electrically controlled switches. Unlike transistors, their switch contacts are electrically isolated from the control input. On the other hand, the power dissipation in a relay coil may be unattractive for battery-operated applications. You can lower […]

App note: Reduced power dissipation of relay loads

Another app note from ON Semiconductors on using PWM technique to reduce power consumed when latching mechanical relays. Link here (PDF) Integrated circuit driver circuits often use relay loads in their application. Output drivers are a source of power dissipation on the IC. Latching relays can be used to keep sustaining load current at a […]

Magic Mote MSP430G2553 wireless sensor node with NRF24L01+ module

Tom from Magic Smoke writes: This is my first time designing a PCB for MSP430. I really like the NRF24L01+ booster pack but I would like something smaller to use for remote temperature sensors. With that in mind I’ve designed a 24.5 x 50 mm PCB (2 on a 5×5 cm prototype) featuring MSP430G2553 and […]

electric imp-Controlled 120VAC relay switcher

Dillon Nichols blog about his electric imp-Controlled 120Vac relay switcher build:     I bought an electric imp about a year and a half ago when they were released. I loved it’s simplicity and made a few temporary projects involving it but wanted to keep it for something more advanced. After all this time, I decided it’s […]

Magic Mote thermostat and wireless temperature sensor

Tom’s another cool project the Magic Mote thermostat and wireless temperature sensor: A homemade thermostat up in the basement rafters controls the heating in my home. The smart bit is the radio frequency communication that connects it to a remote temperature sensor. So, I’m planning a home automation system based around wireless nodes (the Magic Mote […]

Relay control board on DP5031 PCB

Tom writes: Here’s a breakout board for those Songle SRD series relays that are so cheap on Ebay. It fits nicely on the Dangerous Prototypes standard PCB size DP5031. Electromechanical relays are generally employ small signals to switch much higher voltages and currents. As a result, a nice big gap is required to insulate between […]

Switch AC appliances remotely with cellular control

Ezflyr built an AC relay switch that receives commands over the cellular phone network. An ADH8066 quad-band GSM cellular module handles the communication, while a PIC18F2550 controls the relays and reads temperature sensors. The goal of this project is to remotely switch heaters on his aircraft, which requires a few hours of preheating before a […]

Network controlled relays & 3 channel PWM

A new internet controlled lighting project called SplashLight is being developed. It has 4 relays to turn lights on and off, and 3 PWM outputs to drive RGB LEDs. The core of the project is a Cortex M3 uC with an Ethernet PHY/MAC from Texas Instruments. The project includes iPhone, Android, and web applications to […]