Jürgen Beisert writes:
I like the handy DCF77 signal. In this project no clock should use it, instead the computers in my home network should be served by a precise time reference. Due to the fact most other interfaces are no longer available on modern computers, it uses the USB to forward the prepared DCF77 signal to the host.
DCF77 to USB converter - [Link]
Well, our meetings take place on wednesdays at 10:30 (sharp). A radio controlled clock is used to determine whether you are late (and must bring a cake next time) or not. Unfortunately the identical radio controlled clock in my office always shows a different time
After baking a lot of cakes, I thought about synchronising these disreputable clocks …
Homebrew DCF-77 Signal Generator - [Link]
Using a better antenna to improve DCF77 reception on long distances
We are in the prototyping phase of building a Nixie clock using 1N-14 Nixie tubes. The clock is designed around a PIC16F886 MCU, 74141N BCD decoder/driver and CNY74 optocouplers using common circuit topology. High DC voltage (+ 180VDC ) is generated using MAX1771 step-up switching regulator, which is quite efficient (if you use appropriate components).
Our clock will have some nice features:
- Compact design
- Manual time configuration
- DCF77 time synchronization
- Sync success indicator
- HV shutdown during sync (to reduce noise received by DCF module)
- Super-capacitor time backup
- Thermal protection
- ICSP connector etc.
When clock is complete we will release it as open source-hardware here at Electronics-Lab.com
We decided to use DCF77 signal as time reference for two main reasons, it’s quite easy to receive it and it’s very accurate for the reason that carrier signal is generated from atomic clocks.
But, what about receiving and decoding DCF77 signal? Read the rest of this entry »
The DCF77 Simulator is a combined simulator and demonstrator. It generates DCF77 time code at the same time as it displays the code in different views. The time code to be generated can be set to any time between 2000-01-01 and 2099-12-31.
The simulator can control DCF clocks via two interfaces:
- Radio-signal via a built in low-power transmitter
DCF77 Simulator - [Link]
The idea of this project was to build an automatic control for mains heating for the house. The switch turns on the heating in the morning at predefined time and switches off at night. Every weekday can be set at different time points. There can be up to 256 programmable time points and up to 8 output lines that can be connected to relays. Times are programmed via RS232 interface using a command line.
Probably one of most interesting things that differs this project from other is that device synchronizes its time by using DFC77 radio transmissions. So always time is accurate and all daylight settings are applied automatically. DCF77 receiver sends pulse signals directly to PIC microcontroller in desired intervals that must be decoded and applied to current settings. Source code is developed in C and is available for download. [via]
Time switch controller with DCF update - [Link]