Quick Camera battery charger Guide

Accuracy consistent voltage/ consistent existing monolithic adopts monolithic power adapter, geared up with low-power dual operational amplifier and adjustable accuracy identical regulator to develop voltage control loophole as well as existing control loophole. Compared with the control loophole made up of transistors, it has the advantages of high accuracy of consistent voltage and consistent existing, straightforward peripheral circuit, little resistance worth of existing detection resistance, reduced power usage as well as enhancing power efficiency. Its power effectiveness can reach 80%. This kind of power supply is suitable for fast battery chargers of laptops as well as video clip recorders.

The circuit of 15v2a precision constant voltage / constant current output power adapter is shown in the figure. Four integrated circuits are used in the circuit: TOP214Y monolithic power adapter (IC1), PC816A linear optocoupler (IC2), adjustable precision parallel regulator tl431C (C3), and low-power dual operational amplifier lm358 (iC4, including two operational amplifiers ic4a and ic4b).

The circuit has the following characteristics:

  • ① The voltage control loop is composed of ic4b, IC3, vd5, and sampling resistors R3 and R4; The current control loop is composed of ic4a, vd6, and overcurrent detection resistor R6.


  • ② The voltage control loop and current control loop work according to the principle of "logic or gate", that is, at any time, the loop whose output is high level plays a control role.


  • ③ The secondary bias winding NSB is added to supply power to the control loop. The secondary bias can automatically follow the change of DC input voltage you so that it still has constant current characteristics when the power output voltage U is greatly reduced. It will enter the automatic restart state only when u ≤ 0.8V.


  • ④ A TOP214y single-chip power adapter is used, and the rated output power reaches 30W


  • ⑤ When the current control loop composed of the operational amplifier is adopted, the resistance of current detection resistance R6 can be reduced to 0.1q, the power consumption can be reduced to 0.4W, and the power efficiency can be improved.


  • ⑥ Increase the maximum value of feedback voltage u to 46v. Here, PC816A optocoupler is selected, whose U (BR) CEO = 70V > 40V.

Under typical conditions, the voltage control ring functions, as well as the power adapter operates in the continuous voltage location. It enters the consistent existing area when I am close to 2a. Currently, the existing control ring works. The in-phase input terminal of ic4a is gotten in touch with the existing discovery signal ur6, as well as the inverted input terminal is connected with voltage divider voltage ufy. The voltage divider panel is made up of R8, tl431c, and r5. Ic4a outputs a mistake after contrasting ub6 with ufy. The signal U after that becomes a present signal via vd5 as well as R1, moves right into the LED in the optocoupler, and afterwards manages the responsibility cycle of TOP214Y to maintain the output present io of the power supply constant in the continuous current location. Undoubtedly, vd5, as well as vd6, are equivalent to an "or gate". If the present control loop outputs a high degree as well as the voltage control loop outcomes low level, the power supply operates in the continuous present output state; On the contrary, it operates in the constant voltage outcome state.

Post time: May-20-2022