CN202475261U

CN202475261U - Power supply circuit of motor protector

Info

Publication number: CN202475261U
Application number: CN2012200312245U
Authority: CN
Inventors: 闫武林; 白庆生; 柳淑凤; 李懂; 何伟
Original assignee: TIANSHUI 213 ELECTRICAL APPARATUS Co Ltd
Current assignee: TIANSHUI 213 ELECTRICAL APPARATUS Co Ltd
Priority date: 2012-01-12
Filing date: 2012-01-12
Publication date: 2012-10-03
Anticipated expiration: 2022-01-12

Abstract

The utility model discloses a power supply circuit of a motor protector, wherein an input operation voltage can be automatically adjusted within a range of 12% to 120% of the rated voltage while an output direct-current voltage is constant, and both an alternating-current power supply and a direct-current power supply are acceptable for normal operations. The circuit consists of a rectifier and filter circuit, a high-frequency transformer, a control circuit composed of a TOP224Y, two output circuits of 12 V and 3.3 V, and a feedback circuit comprising a optical coupler and a TL431. A feedback signal is sampled at the 3.3 V output terminal, introduced to a reference electrode of the TL431 via a potential-divider network composed of an R3 and an R4, converted to a current feedback signal and input into a control terminal of the TOP224Y after optical coupling isolation, so that the duty ratio of high-frequency power supplies of the source electrode and drain electrode terminals of the TOP224Y is dynamically adjusted to keep the two direct current outputs of 12 V and 3.3 V constant.

Description

The motor protector power circuit

Technical field

The utility model belongs to the low-voltage electrical apparatus field, relates to a kind of motor protector, relates in particular to the motor protector power circuit.

Background technology

The protective device of alternating current motor and similar load thereof; Can transship to motor, protections such as stall, short circuit, phase shortage, anti-phase, and protective device itself needs power supply, this power supply requires to have the input voltage of wide region and stable output voltage; And input power supply direct current is with exchange can both operate as normal; Prior art proposes many schemes to this, but combination property is barely satisfactory, the unapproachable the best of effect.

The utility model content

The utility model technical problem to be solved provides a kind of motor protector power circuit; In 12%～120% amount voltage range, can adjust input service voltage automatically; It is constant to keep output dc voltage to stablize, and imports all operate as normal of power supply AC and DC.

For solving the problems of the technologies described above; The technical scheme of the utility model is: a kind of motor protector power circuit, comprise input rectifying filter circuit, high frequency transformer, by control circuit, two-way direct current 12V and 3.3V output circuit and feedback circuit that TOP224Y forms, and said feedback circuit comprises optocoupler and TL431; Feedback signal is taken a sample at the 3.3V output; The potential-divider network of forming through R3 and R4 is introduced the reference utmost point of TL431, is converted into current feedback signal, again through the control end of input TOP224Y after the light-coupled isolation; Thereby dynamically adjust TOP224Y source electrode and drain electrode end high frequency electric source duty ratio, make two-way direct current 12V and 3.3V output keep stable.

The utility model is through feedback circuit that comprises optocoupler and TL431 and the control circuit of being made up of TOP224Y; Dynamically adjust TOP224Y source electrode and drain electrode end high frequency electric source duty ratio; When the power supply of circuit input was changed in 36～240V scope, the 12V of output, 3.3V dc voltage stability were constant.

Description of drawings

Accompanying drawing is the utility model circuit theory diagrams.

Embodiment

Shown in accompanying drawing, choke L0, capacitor C 1, C2 are ac input circuit, and electric network noise and power supply noise are isolated, and D1, D2, D3, D4 form bridge rectifier, and C3 is a smoothing capacity, and T1 is a high frequency transformer; D7, D8, D9 are rectifier diode, select Schottky diode for use, and C11, C21, C31 are filter capacitor; In order to make filter effect better; In the subordinate of C11, the C21 LC filtering link of having connected respectively, to form by L1, C12 and L2, C22 respectively, the two-way direct current is output as 12V and 3.3V; The potential-divider network that R3 and R4 form, the 3.3V output voltage is input to the optocoupler primary side through resistance R 2 and the adjustable shunting a reference source of three ends TL431, and optocoupler is selected PC871A for use.

When the 3.3V output end voltage raise, the also corresponding rising of the reference pole tension of TL431 was when surpassing normal value 2.5V when raising; Through the effect of TL431 internal circuit, the TL431 cathode voltage reduces, and makes LED voltage rising in the optocoupler and the luminous intensity enhancing; The phototriode conducting strengthens; Equivalent resistance reduces between collector electrode-emitter, causes the control end C voltage of single-chip switching power supply module TOP224Y to raise, and the electric current that flows into control end C increases; The internal control circuit of TOP224Y makes the ON time of internal switch pipe shorten (being that duty ratio reduces); Then the elementary pulse voltage of transformer T1 reduces, and the also corresponding reduction of the induced voltage of secondary each winding makes that finally output voltage is constant; When the 3.3V output end voltage reduces, just the opposite when voltage stabilizing process and 3.3V output end voltage raise.

It is parallelly connected with the primary winding with MOSFET in the protection TOP224Y with the clamp circuit that Ultrafast recovery diode D6 forms that transient voltage suppresses diode D5, and C4, D5 parallel connection can reduce the clamp loss; C5 is used to protect TL431; C6, R1 constitute the self-excitation protective circuit, can eliminate the interference signal of TOP224Y control end C.

Claims

1. motor protector power circuit; Comprise input rectifying filter circuit, high frequency transformer, by control circuit, two-way direct current 12V and 3.3V output circuit and feedback circuit that TOP224Y forms, it is characterized in that said feedback circuit comprises optocoupler and TL431; Feedback signal is taken a sample at the 3.3V output; The potential-divider network of forming through R3 and R4 is introduced the reference utmost point of TL431, is converted into current feedback signal, again through the control end of input TOP224Y after the light-coupled isolation; Thereby dynamically adjust TOP224Y source electrode and drain electrode end high frequency electric source duty ratio, make two-way direct current 12V and 3.3V output keep stable.