These are the circuits and boards of a Mini Temperature Transmitter for a Platinum hundred ohms temperature Sensor. RTD-3W-Transmitter Circuit. See my Transmitter Application Note for this. The customer wanted a two wire system, this needs low power opamps which were ten times the price. If this transmitter works at 3mA it could have [...]
Archive of entries posted on July 2008
AC-AC-SSR Solid State Relay
This is a AC Control Input AC Output SSR Solid State Relay. When a Process Controller has an AC output or a system generates an AC signal of above 100V AC to signal the load to turn on, this device can be used. A BTA40-600 and MOC3041 are used in this. A high voltage plastic [...]
DC-DC SSR Solid State Relay
This is a DC Input DC Output SSR Solid State Relay. It was made for Printing or Photo Processing Equipment. It has an optical isolation and can be used for inductive loads.
The R1 Limits current and Z1 and D1 protects. The 2N3904 limits current in the Opto-Led. When the LED in CNY17-3 turns on, the [...]
Normally Closed AC SSR
This is a Normally Closed PCB Mount SSR. That means when DC Control input is low, the triac is ON, the output passes the load current to turn on small heater-motor-lamp or a bigger contacter-drive etc.
When input DC is high the output is OFF. This is also Optically Isolated from Mains. A Microcontroller output which [...]
