The CA3228 is a monolithic integrated circuit designed as an automotive speed-control system. The system monitors vehicle speed and compares it to a stored reference speed. Any deviation in vehicle speed causes a servo mechanism to open or close the engine throttle as required to eliminate the speed error. The reference speed, set by the driver, is stored in a 9-bit counter. The reference speed can be altered by the ACCEL and COAST driver commands. The ACCEL command causes the vehicle to accelerate at a controlled rate; the COAST command disables the servo, thereby forcing the vehicle to slowdown. Application of the brake disables the servo and places the system in the standby mode while the RESUME command returns the vehicle to the last stored speed. Vehicle speed and driver commands are inputs to the integrated circuit via external sensors. Actuators are needed to convert the output signals into the mechanical action necessary to control vehicle speed.
The Harris CA3228 is a monolithic integrated circuit designed as an automotive speed-control system. It monitors vehicle speed and compares it to a stored reference speed, using a servo mechanism to open or close the engine throttle to eliminate speed error. The reference speed is set by the driver and stored in a 9-bit counter.
| Supply Voltage (Vcc) | 7.40 to 9.00 V |
|---|---|
| Operating Temperature Range | -40°C to +85°C |
| Maximum Stored Speed | 100 mph |
| Speed Resolution | 0.45 mph |
| Minimum Operating Speed | 25 mph |
| Internal Oscillator Frequency | 50kHz |
The reference speed set by the driver is stored in a 9-bit counter.
Application of the brake disables the servo and places the system in the standby mode.