| 摘要 |
A normally closed solenoid valve connects a source of water under pressure to the spray nozzle of a humidifier. An electric switch is connected with the solenoid for energizing it to open the valve. This switch is actuated between on and off positions by means of a normally inactive timer that includes means for holding the switch in each of its positions a predetermined length of time. The timer is provided with means for connecting it in the fan circuit of a forced warm air furnace so that the timer will operate whenever the fan is running.
|
