IV-6 Alarm Clock Fm Radio

© 2018

IV-6 Alarm Clock, FM Radio, USB, MP3 Player

The DIY KIT is based on the IV-3 Time Temp, here with additional Alarm Clock, FM Radion, MP3 Player.  

Someone who has built the IV-3 Time Temp, it should be no problem to build this IV-6 KIT.

Easy construction because the DC-DC Converter + FM MP3 + Amp.PCB are assembled Module.

Here the new OpenSky Case 130mm x 115mm x 42mm.

The DIY Kit all parts incl. Poweradapter and Tubes 60,00€ . Acrylcase + 16,00€


The Circuit.

Unlike the IV-3 Time Temp, the larger IV-6 VFD tubes are used here.


Schaltung und Stückliste




Quartz-controlled VFD watch with pre-set power failure via battery (Litium cell 3 Volt or 4.5Volt)

Display of temperature every 8 seconds, controlled by precision sensor DS18B20. (Like IV-3 Time Temp)

FM, FM radio operation, normal or as alarm function. Mono, as well as stereo operation possible (3 Watt output power)

The brightness of the VFD tubes for night operation is adjustable with a spindle potentiometer and can be switched on using the sliding switch S2 if required, dark operation.

Setting clock and alarm clock via microtaster. FM radio, USB, volume and sound via the remote control

The power supply is a standard USB power supply with 5 Volt 1 A (micro USB connector)


Here the PCB 113mm x 78mm, without AT89C2051, LB1240 and IV-6 Tubes






Power failure.

With this solution, the display, also the radio or USB operation works.

With a 2200mAh battery the IV-6 Clock incl. Fm Radio runs about 3h.

These USB batteries are available, incl. USB cable, from 4.00 €.

The 5 Volt plug-in power supply incl. 1 x USB cable is included in the kit.

When connecting an internal battery, only the AT89C2051 runs without display a short time.