Do you know this:
You have bought something like a wireless thermometer, a radio controlled home-automation device or any other (cheap) radio controlled product and sometimes it does not function or only once in a while or with low range or…
You do not like to experience this with a wireless firing system? That’s why we have summarized what is making the difference between our system and others in terms of all the wireless parameters.
The combination of all these quality features is resulting in the high standard of safety and reliability of the Galaxis wireless firing system:
|Modulation technique||FSK = frequency shift keying||ASK = amplitude shift keying
ASK is much more susceptible to interferences. Radio modules with ASK can be manufactured very cheaply.
|Modulation bandwidth||narrow band, only +/- 3 kHz||The higher the bandwidth of a system the more data can be transferred in a certain period of time but the more susceptible the transfer is regarding to interferences.
Thus some high bandwidth systems are easily disturbed by cells phones or other transmitters if they are operated in proximity. Often insufficient filter circuits are causing similar problems.
Some wireless firing systems even need a high bandwidth transfer because of their system architecture. According to the motto ‘what is normally being sent on a serial data cable is now transferred wirelessly (e.g. via a wireless modem)’
Wireless modem modules – especially if they are ready-to-use – are high bandwidth systems in most cases because the typical user wants to exchange the highest amount of data as possible e.g. between personal computers in a short period of time.
High bandwidth systems are much cheaper to manufacture because there is no need for expensive filters and very precise crystals.
|Frequency band||433/434 MHz||Other frequency bands that may be used with their drawbacks (from an European point of view):
27 MHz: high level of atmospherics, Citizen’s Band band, lots of RC-Cars etc., very big and long antennas required
40 MHz: high level of atmospherics, lots of RC-devices like model planes etc., very big and long antennas required
868 MHz: small number of channels available, this band is unfavourably regulated by the authorities, the radio wave propagation is becoming different (more quasi-optical propagation)
2.4 GHz: here you find the high bandwidth W-LAN and AV systems with all their problems caused by the quasi-optical wave propagation: total signal losses all the way caused by reflections, you have different conditions every 15 cm, previously good connections are suddenly failing due to minimal changes in the surrounding
5.0 GHz: High-Speed-W-LAN, see 2.4 GHz
|Number of radio channels||‘Profi’ series: 32 channels ‘Advanced’ series: 70 channels||The number of radio cannels is not very important. However it isn’t very practical if only a few channels are available e.g. if several systems should be operated simultaneously.|
|Effective radiated power||Standard: 10 mW, higher values upon request
The use of devices with more ERP depends strongly on the regulations of the national authorities. In some countries higher ERP may be used after application by the user and licensing by the authorities. Normally the allowance is connected with annual charges.
|The relevance of the ERP may be overestimated. A good antenna is the best amplifier because to double the range you will have to quadruple the ERP.|
|Receiving method||Double Superheterodyne||If simpler methods are applied selectivity and receiving quality will suffer significantly. Of course money can be saved here also by impairing the quality.|
|Measures for gain control of the received signal||excellent AGC circuit
‘AGC’ = ‘Automatic Gain Control’
|If no such measures have been taken or an insufficient AGC circuit has been implemented the consequence is that the transferred data is being corrupted as soon as the transmitter is being operated to close to the receiver. We know some wireless firing systems that need several meters between the transmitter and the receiver to function properly.|
|Unique transfer protocol||Yes||The use of standard coder/decoder chips as they are manufactured worldwide in unimaginable high volume is a fast solution but bears the potential risk of unintended firing because there could be another user with some wireless device (e.g. garage door opener) that has been programmed to the same code by chance.|
|Unique system code for every customer||Yes||If the user is able to select the system code by himself you never know who is maybe using the same code. This is again a potential risk of unintended firing.|
| CRC check sum
‘CRC’ = Cyclic Redundancy Check
|Yes, 40 Bits + Manchester-Coding||Standard check sums do not provide this level of safety.|
|Approvals, Guidelines, Norms||Allowed to be operated without further application or payment of any charges in many countries.
EN 300 220-3
|Precision of audio source for pyromusicals||PFE Profi Audio
+/- 30 ppm (+/- 0.003 %)
Our crystal controlled audio receiver provides highest level of synchronisation for perfect matching of pyrotechnical effects and music.
|Even if common CD players of well known manufacturers are being used the timing error caused by imprecise clocking can steadily increase to one second or more. Especially when reaching the end of the fireworks display, after some minutes of playing, this timing error leads to a very visible offset.
The human sense of hearing does not detect the slightly different frequencies caused by various playing speed. Therefore the manufacturers have no need to use more accurate and more expensive components for the internal clocking. Instead of high-class crystals often inaccurate ceramic resonators are being used.
Ready-to-use audio modules e.g. for playing back MP3 files like they are sometimes implemented in firing systems are leading often to the same problem.
Translation in progress, please stay tuned…