Simple and practical production of emergency lights. It can automatically switch power supply in the event of a power outage. When the power is normal, the backup battery is automatically charged and has a charging protection function. Its circuit is shown in Figure 1. Here's how it works. When the power supply is normal, J2 is electrically connected, its moving contact is connected with "N/O (normally open)", and the positive terminal of the backup battery is connected with the inverting end of IC1. IC1 (LM308) and D5, D6 form a voltage comparator, and the reference voltage is determined by D5 and D6.
Here, a silicon diode (D5) and a 6.2V Zener diode (D6) are used to form a reference voltage of 6.9V to monitor the charging voltage. When IC1's 2-pin input voltage (both battery voltage) is lower than 6.9V, IC1's 6-pin output is high, T1 is on, J1 is powered, and its moving contact is "N/O (normally open)". When it is turned on, the power supply voltage charges the battery through R2, and LED2 lights up as a charging indication. Change the R2 resistance to adjust the charging current. As the charging time increases, the voltage of pin 2 of IC1 gradually increases. When the voltage is greater than the reference voltage of 6.9V, the 6-pin output of IC1 outputs low emergency lighting level, T1 is cut off, J1 is de-energized, the charging circuit is disconnected, and automatic charging is realized. Protective function.
When the power is cut off, J2 loses power, its moving contact is connected with “N/C (normally closed point)â€, and the battery supplies power to the emergency light circuit through S1, which realizes the automatic switching function when power is off. S1 is used here to manually cut off the emergency light circuit section. The emergency light circuit is composed of IC2 (NE555), T2, T3, T4, X2 and the like. IC2 constitutes a 50Hz signal generator, and 50Hz signal is output from the 3rd pin of IC2. The push-pull circuit consisting of T3, T4 and X2 is driven by T2 inversion and amplification respectively, and 220V AC is induced on the high voltage side of X2 to make the fluorescent tube Light up. The X2 here can directly use the finished power transformer with a secondary voltage of 4.5 volts and a primary 220V, depending on the power of the power test fluorescent tube. When using, pay attention to T3, T4 should be added radiator.
At the time of production, X1 uses a power transformer with a secondary 6V/200mA. J1 and J2 use a relay with a coil voltage of 6V. Other device selections can be referred to the illustration without special requirements. The circuit debugging is very simple. When the main power is turned on, J2 should be activated, and LED1 is the power indicator. Then measure whether the voltage of pin 3 of IC1 is about 6.9V. Then, an external power supply can be used to access the IC2 pin to adjust the charging protection circuit. When the input voltage is greater than 6.9V, J1 should be disconnected. Short open S1, use external power supply to connect to the emergency light circuit, measure whether the output of IC2 is 50Hz, and then measure whether the voltage of X2 output part is about 220V. LED3 is an indication of power failure/emergency light operation.
The 20V Cordless Circular Saw is Perfect for Cutting Wood, especially on Bevel Cutting and Straight Cutting, compared to the Jig Saw.
The 20V Cordless Wood Working Circular Saw is convenient to use at anywhere, wireless power supply, 4Ah and 2Ah Battery is rechargeable.
4Ah battery can cut around 30m wood.
This Cordless Power Tool is designed friendly, can be used by Left or Right Hand.
It is a cordless wood cutting power tools that users feels much better, compared to jig saw.
The Cordless Wood Working Power Saw with single speed 4000rpm, Laser Function, Bevel Cutting 45°, 55mm cutting depth at 90 Degree, 36 cutting depth at 45 Degree.
The Cordless Circular Saw With a dust blower for max cut -line visibility.
The Cordless Wood Cutting Power Tools with protection button for your safety, soft rubber handle for comfortable use.
Cordless Circular Saw,Portable Circular Saw,Cordless Circular Saw With Battery,Hand Circular Saw
Ningbo Brace Power Tools Co., Ltd , https://www.bracepowertools.com