(Click photo for larger image)
Wireless Operated Replica Mines (WORM)
A small imitation anti personal land mine used for testing de-mining equipment. Full details at: WORM Brochure
100-0050 Motor Driver - Using the L293E and a Programmable Logic Array this dual H-Bridge driver can serve as either a Stepper Motor Controller or a twin DC motor controller. What makes this device unique compared to other L293 based drivers is the 'E' suffix on the part. The emitters of the H-Bridge driver transistors are brought out of the package and along with a comparator, reference and logic the board has the ability to use a 'Chop' mode current control.
This allows DC motors to turn very slowly with large amounts of torque because short high voltage pulses are applied until the current reaches the armature's rating. Similarly, Step Motors are able to move quickly because the higher voltage causes the rated current to build up much faster than an equivalent lower voltage controller. This means full torque is available much sooner and allows the motor to step at higher speeds. Unlike the LR drives, which hold the current to the rated value with a large high power resistor, the 100-0050 regulates the current and maintains the torque by efficiently switching the drive on and off.
The PAL logic also safely disables drive to the motor when an optically coupled limit switch is reached. A change of state on the DIRECTION input then allows the motor to move away from the energized limit. There is an additional optically coupled switch that can be used as a HOME position input.
Designed for FIREWALL FORWARD Aero Engines Inc., this product was created to replace and improve an existing design. The criteria for the new product was that it should be in an extruded aluminium case with sufficient room for future expansion. Additional circuitry was added to protect all external inputs. An extra processor was also designed in to convert the engine RPM to Propeller RPM and energize the VTEC solenoid on the HONDA engines.
The photo you see the first prototype. Surface mount components were used to reduce weight and create a more secure board, protected against vibration and to allow high quality machine fabrication for much of the components.
Click on the photo to see the production version being tested and a sneak peak at the new ignition/injection system with built in CAN bus for communications to the instrument panel.