International Fireworks Competition Hannover, Germany

The Voltcraft Power Monitor Pro is a digital instrument that measures voltage, current, frequency and phase angle on a single phase mains operated device. The measurements are supplemented with intelligent features to instantly display power and energy consumption, trace minimum and maximum values or to clock operating times.

Again this is a cross marked „out-of-the-plastic-box“ unit and it lied around under my desk for at least a year until I remembered its existence a few days ago after having done my taxes. Tax declarations are anything but a favourite pastime, you know, and faulty measurement devices are a perfect compensation in my opinion.

The Power Monitor seemed to work properly as the display showed the default screen on power-up. However, it just always displayed 0 volts and 0 amperes and did not measure anything except from the 50Hz mains frequency. So I opened the plug unit first to see what was going on.

The plug unit contains a small PCB with a shunt wire, a 1µF MKP capacitor and a 100Ω resistor. The shunt wire is connected in series to the load under test and allows measuring the current. The series connection of capacitor and resistor and panel unit electronics is connected in parallel with the mains supply. This circuitry is a cheap and resonable alternative to using a mains transformer in case you both have only a small load to supply and do not need galvanic isolation. No defective parts in here.

Opened up the panel unit and checked the cable connections from panel to plug. One may think that broken cores should be too easy to be suspected but on the other hand there is nothing more obvious to be checked next.

Besides mostly SMD parts on the panel unit there are a few conventional through-hole components that, in combination with the already mentioned capacitor and resistor in the plug unit, form the voltage supply and stabilization circuit. In fact, the Power Monitor requires a symmetric supply voltage of +/-5V. This is achieved with the positive and negative half cycles running each through a 1N4001 rectifier diode in series with a BZX55C15 Z-diode to limit the peak input voltages on the following two 78L05 and 79L05 voltage regulators.

There is a rule of thumb saying that a malfunctioning power supply is the cause of about 90 percent of all failures. This rule prove true again when I found the Z-diode in the negative leg to show a voltage drop of 86mV in both directions. Replaced it with a standard ZPD15 and also replaced the 79L05 voltage regulator although, to be honest, I did not check if this was really necessary. Now the Power Monitor is fully operational again and meanwhile monitoring my fridge.

The Voltcraft Cable Checker comes in a set of 9V battery powered transmitter and receiver and allows you to check and identify up to 16 cores in a cable at a maximum resistance of 25kΩ. A possible usage scenario is testing cables with indistinct colour code, preferably on a wide distance across rooms or buildings and with only one person. Just connect the terminals 1~16 and circuit ground of the transmitter on one end and the receiver will indicate the number of each core on the other end.

Of course, the Cable Checker is another episode of these cross marked out-of-the-plastic-box units and again it was at least a little bit faulty when I took it home. Hey, don’t you like faulty toys?

The receiver worked fine and so did the transmitter, except for channel 6 which was dead. After opening the box I saw three CMOS 4049 UBCN driving the terminals without additional protection. So, this is why the manual says that „applied voltages in excess of 7 V DC or AC will damage the transmitter and it is therefore crucial to make sure that the cable under test is dead“.

Even with respect to the price the Cable Checker is a cheapo and it will die instantly if you forget to think before connecting it. As thinking is sometimes a difficult business, I decided to install three IC sockets for the drivers. The PWM signals generated by the transmitter are shown on the scope for channels 1 (top) and 8 (bottom) at 5ms/DIV.

The receiver is based on an 8031 compatible Atmel 89C1051 microcontroller with 1K bytes internal flash memory. It directly drives a standard 3½ digit LCD. This box is the most expensive part of the Cable Checker and its only input is well protected with a resistor and two diodes.

Salto Musicale, Kleines Fest im Großen Garten Hannover, Germany

ClickTrack is a little tool for easily adding click tracks to your Standard MIDI Files (.mid). Click tracks are almost indispensable if you play live with both a sequencer (machine) and a drummer (human) and the human is acting as a timeline-slave to the machine.

The story
Keyboarder uses sequencer and is fed up with bad timing of Drummer at last gig. Drummer is always fed up with Keyboarder, but this time Keyboarder has gone too far as Drummer did not hear anything from him at all over the monitors. So Keyboarder adds click tracks to his sequences and Drummer borrows a set of headphones from Girlfriend and henceforth performs straight to the tic-toc-toc of the sequencer. Guitarist does not take part in this discussion. He was clearly audible on stage, shouldn’t this be enough anyway?

The truth
A good friend of mine asked me for help to make all his tens of MIDI files contain those click tracks. After trying to rework some files manually in Cubase we decided that it would be much nicer to have a tool like ClickTrack.

About Standard MIDI Files (SMF)
SMF are a common and standardized way to interchange time-stamped MIDI data between computers or MIDI devices. The file format has been specified by the MIDI Manufacturers Association (MMA). SMF are often used on stage for playback with hardware sequencers, and this is the only file format that can be processed with ClickTrack.

• SMF Format 0
  Format 0 files comprise of one track that may contain MIDI data on all channels 1~16. Additionally, all meta events like tempo, time signature or lyrics are located in this one track. Format 0 is especially suitable for load-while-play devices due to linearity between time- and fileposition of events.
• SMF Format 1
  Format 1 files comprise of up to 65536 tracks. Track 0 is kind of a mastertrack, usually hidden to the user and containing meta events like songname, tempo and time signature. Tracks 1~65535 are the ones you see in your sequencer application and that each may contain MIDI data on all channels 1~16. Format 1 is especially suitable as interchange format for complex arrangements with more than 16 part multitimbrality and for dedicated routing of tracks to MIDI outputs on hardware sequencers. Not many load-while-play devices support format 1 as timely subsequent events are staggered trackwise along the file.

It is important to realize the differences between format 0 and format 1 to select the most appropriate variant for your application. ClickTrack allows you to load, process and save files of both formats, and thus it may also be used as a conversion tool. Furthermore, it offers a few goodies to edit song- and tracknames, to intelligently transpose songs and tracks, to reorder or mute tracks and to remap MIDI channels.

Menu File
Files can be opened as usual but drag & drop is supported and recommended. There is no Save option but only Save As.. instead to avoid erroneous overwriting of your original files.

Menu MIDI
There is an Offline option to close the MIDI output and make it available to other applications without closing ClickTrack. May be useful.

Song Info
The Song Info shows the name of the song and offers a global transposition combo box. The songname is not the filename but the meta event trackname of track 0 in a format 1 file or the one and only trackname in a format 0 file. Double click on the songname field to set or change this value. Global transposition means that all note events not on channel 10 and all tracks not mapped to channel 10 are transposed. MIDI channel 10 is usually used for drums.

SMF Info & Save Options
The SMF Info displays the format of the SMF, the number of tracks and the division. If you load format 0 files, the number of tracks is set to 16 at first, as channels are mapped to tracks. Within the Save Options you may change the format to be saved and the division value. If you do not know about the division parameter you should let the combo box setting on Keep.

Tiny Tracklist
The Tiny Tracklist provides a quick overview on the tracks. If you click the check box beneath a trackname the track will be muted while playing. Additionally, muted tracks, when saved to format 1, will still exist to keep up the track order but will contain no note events. Muted tracks, when saved to a format 0 file, will be deleted concerning their note events. Double click on a trackname to set or change the value but be aware that tracknames will only be saved with format 1.

The four combo boxes on the right allow you do some track specific modifications. The Channel option, when set to any after loading, indicates that the selected track contains MIDI events on more than one channel, otherwise it is set to the appropriate value. To force events on this track to be put out an a specific channel, just set it on the desired value. With the Transpose combo box you may transpose all note events on the selected track by value -24~+24. Just in case the track sounds too bassy low or too screamingly high after transposition, you may force a certain key window for all note events with the Wnd bot and Wnd top combo boxes. Any notes below or above the given key window will be wrapped one octave above or below the original value. This often leads to very interesting results, maybe try it on the bass track first.

Click
The Click options should be generally obvious. Imagine you have a 16 track format 1 file and want all your files to have a click track 20 in the future. Just set the Track combo box on value 20 and go for it. If you leave it on value 10 and your drum parts are on track 10 then the click track will be merged into the existing track.

Select accent and default note with the Acc and Def combo boxes. Of course, for proper positioning of accent and default note, the MIDI file must contain time signature events. If it does not, you may work around by setting these notes on the same value. Adding a click track may not be undone currently, this is yet a one-shot feature so you should always add the click track finally after having played with the tracklist options.

Download
ClickTrack is built with Borland C++Builder 6 using Theme Manager by Mike Lischke. It is designed to run on Microsoft Windows 2000/XP and comes with Inno Setup installer. Please tell if you find errors or want further features to be added, your feedback is welcome.

ClickTrack is freeware and provided to you as is. It is assumed to work properly but may be erroneous and have malicious effects on your computer systems or MIDI devices. Download and use at your own risk.

Download ClickTrack 1.0 (~613KB)