Constant-current charging circuit for super capacitor

Abstract

The invention belongs to the technical field of charging management, and discloses a constant-current charging circuit for a super capacitor. The circuit comprises a charging power supply, the charging power supply is connected with the super capacitor through a constant-current unit, and the constant-current unit comprises an enabling trigger module and a resettable fuse PPTC which are connected together. The two ends of the super capacitor are further connected with a voltage detection module in parallel, the voltage detection module is used for detecting voltage signals at the two ends of the super capacitor, the voltage detection module, the enabling trigger module and the temperature detection module are all connected with the processor, and the temperature detection module is used for detecting the environment temperature; the processor is used for controlling the resettable fuse PPTC to enter a high-resistance state through the enabling trigger module according to the received environment temperature and voltage signals, and constant-current charging of the super capacitor is carried out.

Description

technical field [0001] The invention belongs to the technical field of charging management, and in particular relates to a constant current charging circuit for supercapacitors. Background technique [0002] As the use of supercapacitors becomes more and more popular, the management of charging and discharging of supercapacitors becomes more and more important, especially in the field of automotive electronics, the performance requirements for the charging circuit of supercapacitors are very high, which requires extremely low radiation and conduction disturbance level, and requires low price and small size, so various new low-cost charging circuit applications are born. [0003] The traditional step-down constant current charging circuit basically adopts two methods, one is the PWM control method, such as BUCK, BUCK-BOOST and other topological structures, for the charge and discharge management of small-capacity supercapacitors (supercapacitors with a capacity less than 20F ...

AI Technical Summary

Problems solved by technology

[0003] The traditional step-down constant current charging circuit basically adopts two methods, one is the PWM control method, such as BUCK, BUCK-BOOST and other topological structures, for the charge and discharge management of small-capacity supercapacitors (supercapacitors with a capacity less than 20F In terms of capacity), its radiation and conduction need to spend a relatively high cost to meet the requirements of automotive electronics, and the volume is relatively large, which is not an ideal solution; the other is a linear charging circuit, which has obvious disadvantages. When charging from 0V, the voltage drop from the input voltage to the output voltage is relatively large, and the voltage drop and loss are all borne by the linear circuit, so the loss of the linear circuit is a big problem. At the same time, a relatively large heat sink is required, so the volume and heat dissipation become A problem, and the cost of the linear circuit will increase exponentially with the rise of the charging current, which cannot meet the needs of customers

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