I helped out another Blitzortung lighting user by building up his kit, this one is now up an running in St Thomas, Virgin Islands, the pictures below show the various stages of PCB build, the firmware program and that the GPS has picked up satellites to time lock the strikes.
Red Arrows show location of St Thomas detecting lightning 2,300 miles away!
Updated 8 June 2023
This Blog post went into detail on the sensors used for the mast position, I have found reasonably priced ferrous metal inductive proximity switched, these are non contact devices with a detection range of 5mm which is perfect for my application of securing pin detection, feeding into the masts PLC logic controller.
Sensor mounted below bottom mast securing pin hole, the sensor was fixed the mast by drilling and tapping a 6BA hole, the HSS drill size of 2.3mm for a 6BA tap cost 99p for 10 from Hong Kong, the machine screws which come with the sensor appear to be imperial and were discarded.
Test position for alignment and operation checking.
Lower pin sensor finished with a three pin male Superseal waterproof connection, the female will break out of the 10mm convoluted conduit via a hinged tee piece.
Top mast securing pin sensor being fitted, this pin stops the mast from tilting down (Luffing), the output from this sensor, like the bottom pin detector will influence the functions available in the PLC controller, for example, if the mast is elevated and the top pin is removed, the mast will not lower as this is an unsafe condition.
The next stage is the mounting of the controller cabinet and wiring which can be found HERE.
Update 20 July 17 – Top proximity failed and had to be replaced, no sign of water ingress and the potting and cable entry look in good order, so not sure what the cause of the failure.
Extrernal Link to Inductive Proximity Sensor Technology blog.
This blog is an update of this – Pan & Tilt Orbitron Interface post as I’ve added some pictures of the kit used and I have finally got round to putting the Rotorcards in a decent enclosure.
The main controller is a ERC-M USB kit which interfaces with the PC and programs which are running , the Rotorcard relays are controlled by the ERC-M, the Rotorcard also provides a positional feedback to the ERC-M.
Front panel of the Desktop housing for the ERC-M, the front panel has manual buttons for up/down tilt & left/right pan, LED’s also show when a signal is sent to the Rotorcard relays.
The two yellow LEDs on the left hand side indicate the signal to the auxiliary relay.
The LCD display is showing the position in degrees, the number after Az or El is the feedback from the Pan & Tilt head, the numbers on the other side of the > are the output from the software, the ERC-M compares the two values and energises the appropriate relays which in turn operate the motors in order to keep the values aligned.
The ERC-M kit is the top left PCB, the desktop housing is also a kit comprising of the LCD display and front panel buttons.
The PCB mounted inside the desktop housing is the 13.8v to 10v voltage regulator which provides a stabilized supply to the Pan & Tilt heads positional potentiometers.
An external 13.8v supply is required in order to drive the high current motors of the Pan & Tilt head.
The two Rotorcards (one for Pan the other Tilt, or more correctly Azimuth and Elevation respectively) are enclosed, 13.8v can be fed to the relays here or at the desktop housing.
The three outputs from the ERC-M enter on the right hand side to the Rotorcards, the middle connector is the 13.8v – 0v – 10v supply.
The top Rotorcard relays operate for clockwise or anticlockwise supply to the Azimuth motor, the third relay is not used (auxiliary relay) as the Pan & Tilt head does not have an electro-mechanical brake fitted, if it did, relay three would operate in advance of the motor supply relays.
The bottom Rotorcard is for elevation, Up & Down.
On my version, the ERC-M is connected to a PC via a USB connection to Com Port 6, the position of the heads has already been calibrated using the provided software from Easy Rotor Control.
To start tracking satellites, the first step is to open Orbitron.
This is a free download program, each time it is ran, check that the TLE files have been updated then select the satellite of interest from the right hand list, once this is done, click on the satellites on screen icon.
On the bottom tabs, select rotator and click DDE a small box should now open on the screen with live positional data of the selected satellite showing, (a separate download is needed for the DDE function).
Open PST Rotator program:
Using the PST Rotator settings configure the program to respond to Comm Port 6, use Orbitron as the controlling program, that the type of head ouput is GS-232 and Az/El is selected.
When the program is set to ‘Track’ as the above image, the displays show the actual position of the Pan & Tilt head by a black line with the green line showing where the head needs to move to, the green line is controlled via DDE from Orbitron.
A further setting I have enable is the link to weather information, this allows the mast to rotate into the wind when a trigger speed has been reached, this reduces wind loading on the mast and antenna.
This is a Dennard CCTV Pan & Tilt head and operates at 24v, 13.8v works it just fine with a maximum current draw of 600mA, I have commoned the potetiometers supply, so the minimum number or wire cores is 8:
2 – Pan Motor
2 – Tilt Motor
2 – 10v supply across positional potentiometers
1 – Signal feedback from Pan
1 – Signal feedback from Tilt
The next stage is to get some decent antennas for satellite reception.
