Tag Archives: construction set

Temperature sensor for IV-11 DCF melody

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A functional update for the IV-11 DCF melody watch is available from gr-projects. It is a radio temperature transmitter. The special thing about it is, that the transmitter operating in the ISM band 433 MHz is equipped with a photovoltaic cell (solar cell). Depending on the version, a small rechargeable battery or a CR2032 button cell can be installed in the transmitter. The battery is thus supported by the solar cell in the sunlight or in the battery version it is charged during the day and then keeps the transmitter in operation over the dark time.

The assembly is easy. The kit consists of a transmitter and a receiver. The boards of transmitter and receiver are equipped with few components quickly. Here, however, some attention is required and you should read the documentation carefully, because due to the lower number of kits, the boards are manufactured without component imprint and solderstop.

transmitter module

The radio modules themselves are completely pre-assembled (SMD) and only need to be soldered into the corresponding circuit boards. Optionally, a trim potentiometer can be connected in parallel to the temperature sensor (NTC) for adjustment purposes. The transmitter, like the receiver, is installed in a small PVC housing. Here, except for a 3mm drill hole and possibly some silicone for the sealing of the solar cell (for operation outside the window sill) no further tools are needed.

transmitter complete with PV-cell

To connect the receiver to the clock, make a few minor changes to the clock’s mainboard. First, the microcontroller is replaced – logically – because there is indeed a new program that then displays the temperature in the date line. A resistor is removed, one is added and a jumper can be swapped. The connection between the clock’s motherboard and the radio receiver is made with a piece of cable. Three lines are required (GND, + 5V and the data signal from the receiver controller to the clock controller). That’s it then already. The clock can go into operation. After a few seconds, the received temperature is displayed in the tube.

receiver in it´s case

 

A video how to solder the circuit is available here:

Taster day in technology

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In the last two days we received a visit from two young gentlemen from the fourth year of the Villach High School Sankt Martin. Mr. Martin Ungermanns and Mr. Fabian Treu came to us as part of a “taster program” of the middle schools. The two students can participate in the “world of work” and get some insights into the technology.

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deepened in the soldering work

The program included work such as assembling and soldering of electronic kits (the well-known shaker cube), a small series work (flashing of PIC microcontrollers), exposure and etching of circuit boards, milling of aluminum plates.

As conclusion of the two taster days both high school students were allowed to build up a complete “device”.

 

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Martin Ungermanns and Fabian Treu

It was a “clap switch kit” that detects a loud sound event via an acoustic sensor and then turns on a relay contact. So that this circuit can also be used meaningfully, the circuit has been extended by a self-made power supply, all installed in a plastic housing and equipped with power cable and Schuko coupling. So any consumer (eg a floor lamp, TV) can be switched on and off with this switchgear by simply “clapping” …