Borgelt B400 Variometer
General Description
The Borgelt B400 (Variometer with Audio and Averager) designed to replace mechanical variometers with modern technology with more useful features.
Built in audio, push button averager and unique to Borgelt Instruments, climb optimizer – green LED lights when vario is above 20 second running average reading – that is, average is getting better. You can select an audio change at this point also.
The B400 is designed to replace the well known B40 variometer and like the B40 is aimed at replacing the old technology mechanical variometers in the instrument panel of cross country and competition sailplanes as well as providing a good variometer with useful extra features (audio and averager) for club and training sailplanes.
The B400 is available in both 57mm and 80mm sizes for easy installation in existing instrument holes and is only 85mm deep behind the panel including connectors (20mm shorter than the B40).
A standby power pack of 4 x AA alkaline batteries will provide at least 7-8 hours of operation in the event of main power systems failure.
A remote press button circuit or button in lower left enables the pilot to select the 20 second running average rate of climb at any time. The audio continues to function as a variometer during this time.
The B400 uses surface mount technology in the electronics and the variometer display is by a small stepper motor driven pointer plus two high brightness LEDs. This provides the display with far better resolution and contrast than the LCD type pointers under all the changing lighting conditions typical in a circling sailplane. The display resolution is around 1/40 of a knot. This means a far smoother indication and much faster recognition of which way the pointer is moving particularly if the lift is weak. This is nearly 20 times the resolution of typical LCD pointers.
Audio is full range with silent zone from 1 to 4 knots sink or “Up” only and there are two styles – “B40 Classic mode” with solid tone in sink (when full range selected) and 50:50 chopped tone in lift and a “competition mode” as follows: At –10 knots (–5 m/s) the audio begins with clicks which become closer together as the sink decreases and then become a rising tone with the tone being chopped in lift. When the lift is above the running twenty second average the tone is chopped 50:50, when the lift is below the running average the tone is 70 on:30 off. Style selection is by a small potentiometer accessible through a small hole in the rear cover of the instrument.
Volume control is by a center off toggle switch in the upper right mounting screw position.(B400).
The instrument is supplied with an external speaker with case and mount. This avoids problems with the speaker magnetic field causing compass errors as the speaker can be remotely mounted which also helps audibility.
Operation
On power up pointer goes full down for a few seconds, then back to zero, red and green lights near zero point flash on momentarily then vario is ready to use a few seconds later.
Audio volume is set to a reasonable level and is adjusted by the toggle switch in the top right mounting hole position. Moving the toggle left and up increases volume, right and down decreases volume.
The push button switch in the lower left position has two functions. When pushed and held down it causes the pointer to read the 20 second running averager value on the pointer while the audio remains on TE vario. This button is in parallel with the two screw terminals marked “average select” on the XCB. A remote push button switch may be connected to them. When pushed momentarily it causes the audio to switch between “up only” and “full range (up and down)” modes. When switching from “up only” to “full range” the red and green lights flash rapidly for a second or so. When switching from “full range” to “up only”, only the green light flashes.
