)
ON period from 6 seconds to 60 minutes
OFF period from 6 seconds to 60 minutes
New Improvements & Features
This new version of the CK191 offers the following additional features as compared to our original design:
1. On and Off LED Indicators.
2. Professional Screw-on Terminals for relay output as well as an on-board DC jack for easy connection to a DC adapter.
3. Optional Custom Enclosure (Part Number BX-191) with silk screened custom panels.
4. Greatly Improved Accuracy. Our original design was a conventional timer based on the popular 555 timer integrated circuit. All 555 based timers suffer in accuracy due to the fact that the timing period is based on the voltage across an electrolytic capacitor.
Our new design is much more accurate as its based on counting the frequency of an oscillator. The design is based around two 4541 Programmable Timer Integrated Circuits which will send a signal to the relay circuit once it reaches a specific count of cycles generated by the oscillator. The oscillator’s frequency is varied by the variable resistor which results in different timing periods.