Abstract: Mechanical timer is a relatively primitive timer. It uses spring as the power source and is mainly composed of three parts: spring, gear transmission mechanism and time control component. Its principle is the same as that of mechanical timer. The principle of a clock is similar. After winding up the clockwork, the gear transmission mechanism changes speed so that the gear train rotates constantly under the drive of the clockwork. When a gear in the gear train rotates to a certain angle, the timing trigger device sends out a signal to control the circuit. Turn on and off or sound audible reminder. Let’s take a look at the structure and principles of mechanical timers. 1. What parts does a mechanical timer consist of
A mechanical timer is a timer that uses spring as its power source. It is similar to a mechanical clock, but the difference is that the mechanical timer When the time reaches the specified scale, the switch will be triggered, thereby sending out an electrical or mechanical signal to stop power supply or sound a bell. The structure of a mechanical timer is mainly divided into three parts:
1. Clockwork
It is made of elastic steel strips. When used, the clockwork is tightened manually through the knob. Potential energy is stored, and when the mainspring relaxes, it releases the stored potential energy and transmits power to other parts of the timer.
2. Gear transmission mechanism
The gear transmission mechanism is an intermediate mechanism that transmits the potential energy of the clockwork to the time control component. According to the different gear clutch modes when winding the clockwork, mechanical Timers can be divided into three transmission mechanisms: spring tube type, pawl type and small spring type.
3. Time control component
The structure of the time control component of the mechanical timer mostly uses one or two sets of cams to allocate time. When the control cam rotates, it continuously changes its structure. The convex and concave positions enable the contacts of the relevant contact reeds to be connected or disconnected according to the design requirements to control operation and stop.
The mechanical timer is a single-circuit design with precise structure, low failure rate, and does not require the use of batteries or other power, making it very practical.
2. Introduction to the principle of mechanical timer
The internal structure of the mechanical timer is actually similar to that of a mechanical clock. Its principle also draws on the principle of a mechanical clock. The specific working principle is:
The mainspring is tightened to provide power for the entire system. When the mainspring is released, the gear transmission mechanism changes speed, which increases the number of rotations when the mainspring is relaxed. There is an escape wheel and escapement claw at the end of the gear system. and a hairspring to ensure that the gear system rotates at a constant speed driven by the spring. There is a device on the hairspring to adjust the length of the hairspring to adjust the frequency of the escapement claw swing and ensure that the gear rotates at the set speed; when a certain speed in the gear system After the gear rotates to a certain angle, that is, after the set time is reached, the timing trigger device will send out a signal.
To put it simply, the working principle of a mechanical timer is to turn the timer to provide power, and then turn it back. The turning scale sets the triggering position of the trigger mechanism. The entire structure is controlled by the escapement wheel. Next, slowly release the power of the clockwork, and the gears at all levels begin to rotate at a constant speed until the mechanism is triggered.