A resistance-capacitance step-down power supply circuit for a smart toilet seat heating

Abstract

The utility model provides a kind of for intelligent toilet seat heating resistance-capacitance voltage reduction power supply circuit, including following module:‌ voltage reduction capacitor,‌ bleeder resistance,‌ rectifier circuit,‌ voltage stabilizing element and‌ filter capacitor, the voltage reduction capacitor is for 220V alternating current to be reduced to 5V direct current, bleeder resistance R12 and bleeder resistance R13 are together in series then parallel in the two ends of the voltage reduction capacitor, the anode of the rectifier circuit is connected the output end of the voltage reduction capacitor, cathode output pulsating direct current, the voltage stabilizing element is made of parallel voltage stabilizing diode D1 and voltage stabilizing diode D3 and current-limiting resistor R1, the filter capacitor is parallel in the voltage stabilizing element output end;The utility model can be realized for 220V alternating current heating piece power regulation and low voltage control unit power supply, especially suitable for the safe and efficient control of intelligent toilet seat heating system.

Description

Technical Field

[0001] This utility model relates to the field of AC power control technology, and in particular to a resistor-capacitor step-down power supply circuit for intelligent toilet seat heating. Background Technology

[0002] Current smart toilet seat heating systems generally use traditional switching power supply solutions, which have the following technical drawbacks:

[0003] Complex structure: Traditional solutions require the combination of multiple discrete components (such as transformers, rectifier bridges, filter capacitors, etc.), which leads to difficulties in PCB layout and increases costs by more than 30%.

[0004] Standby power consumption: Traditional solutions consume ≥2W in standby mode, resulting in low energy efficiency during long-term operation;

[0005] Too large: The separate design makes it difficult to meet the installation requirements of the compact structure of smart toilets;

[0006] Heat dissipation issue: High-power transformers generate high temperatures during operation, posing a safety hazard;

[0007] High maintenance costs: The entire power supply system needs to be replaced if a single component fails. Utility Model Content

[0008] In view of this, the purpose of this utility model is to provide a resistor-capacitor step-down power supply circuit for intelligent toilet seat heating, which can realize power regulation and low-voltage control unit power supply for 220V AC heating element, and is especially suitable for safe and efficient control of intelligent toilet seat heating system.

[0009] This utility model is implemented using the following method: a resistor-capacitor step-down power supply circuit for intelligent toilet seat heating, comprising the following modules: a step-down capacitor, a bleed resistor, a rectifier circuit, a voltage regulator, and a filter capacitor. The step-down capacitor is used to step down 220V AC to 5V DC. The bleed resistors R12 and R13 are connected in series and then in parallel across the step-down capacitor. The anode of the rectifier circuit is connected to the output terminal of the step-down capacitor, and the cathode outputs pulsating DC. The voltage regulator consists of a parallel Zener diode D1 and a Zener diode D3 and a current-limiting resistor R1. The filter capacitor is connected in parallel to the output terminal of the voltage regulator.

[0010] Furthermore, the surfaces of resistors R12 and R13 of the bleeder resistor are coated with conformal coating to meet the IPX4 protection level.

[0011] Furthermore, the bleeder resistors R12 and R13 are connected in series and then in parallel across the step-down capacitor. When the power is off, the step-down capacitor discharges to prevent electric shock.

[0012] Furthermore, the total resistance of the bleeder resistor is 1MΩ.

[0013] The beneficial effects of this utility model are as follows: The utility model has a simplified structure and lower cost; fewer components are required: only basic components such as capacitors, resistors, and rectifier diodes are needed, eliminating the need for high-frequency transformers or complex control chips, reducing hardware costs by 40%~50%; compact layout: the size is reduced by more than 60% compared to traditional switching power supply solutions, making it suitable for space-constrained scenarios such as smart toilet seats; low standby power consumption: the static current can be as low as μA, and the standby power consumption is ≤0.1W (traditional solutions ≥2W), meeting the energy efficiency requirements for long-term operation of smart toilets; fast dynamic response: the energy storage characteristics of the capacitor enable the circuit to respond to sudden load changes in less than 10ms, adapting to the real-time requirements of PID temperature control algorithms; adaptive to grid fluctuations: through parallel adjustable capacitor banks, the input voltage can be adjusted to 170... When fluctuating within the range of V~250V, the output voltage deviation is ≤±3%; Strong anti-interference: No switching components are used, avoiding electromagnetic interference (EMI) from high-frequency noise to sensitive circuits such as MCU and temperature sensors; Natural isolation characteristics: Safety capacitors (X2 / Y type) provide double insulation, meeting the IPX4 or higher protection level requirements of smart toilets; High fault tolerance: In case of short circuit or overload, the current-limiting resistor will melt first, protecting downstream circuits (such as MCU and thyristor) from damage; Environmental compatibility; Wide temperature range: Supports ambient temperature from -20℃ to 85℃, adapting to the complex working conditions of bathrooms with humidity and alternating hot and cold temperatures; Long life design: Without electrolytic capacitors (using film capacitor solution), the circuit life can reach more than 100,000 hours, significantly higher than traditional switching power supplies. Attached Figure Description

[0014] Figure 1 This is a circuit block diagram of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings.

[0016] Example 1: Implementation of Basic Circuit

[0017] Component selection and parameters

[0018] Please see Figure 1 As shown, the step-down capacitor (CX1) is an X2 type film capacitor with a capacitance of 0.47μF, a tolerance of ±10%, and a withstand voltage of AC275V (such as the EPCOS B32922 series); it is a core current-limiting component.

[0019] Leakage resistors (R12 and R13): carbon film resistors with resistance values ​​of 510kΩ and 490kΩ respectively, tolerance ±5%, and power 0.25W; they are connected in series and then in parallel across the step-down capacitor (CX1) to discharge the step-down capacitor (CX1) when the power is off, preventing electric shock.

[0020] Rectifier circuit (D2): Model 1N4007, reverse withstand voltage 1000V, forward current 1A; half-wave rectification;

[0021] Zener diodes (D1 and D3): Model BZX55C5V1, regulated voltage 5.1V, tolerance ±5%; Zener diodes ensure stable output voltage;

[0022] Filter capacitor (C10): Polyester film capacitor, capacitance 100μF, withstand voltage 25V (such as WIMA MKS2 series); used to smooth output voltage, usually an electrolytic capacitor;

[0023] Workflow

[0024] Charging phase: During the positive half-cycle of AC, the capacitor is charged through the rectifier diode, and the current forms a circuit through the load;

[0025] Discharge phase: During the negative half-cycle or when the input voltage drops, the capacitor discharges to the load to maintain a stable output voltage;

[0026] Dynamic balance: The capacitor-resistor network continuously adjusts the current distribution to offset the impact of power grid fluctuations on the output.

[0027] Circuit connection

[0028] The AC input L terminal is connected in series with CX1 and R12-R13 in parallel, and the N terminal is directly grounded;

[0029] The output terminal of CX1 is connected to the anode of D2, and the cathode of D2 is connected in sequence to R1, the parallel group of D1 / D3 and C10;

[0030] Workflow

[0031] During normal operation: 220V AC power is stepped down by CX1, then half-wave rectified by D2 into pulsating DC, and then regulated to 5V by D1 / D3. C10 filters out ripple and then supplies power to the load.

[0032] Fault protection: When the load is short-circuited, R1 will melt due to overcurrent and heat, cutting off the power supply to the subsequent stage to avoid damage to the MCU or temperature control components.

[0033] Example 2: Low Temperature Environment Adaptation Solution

[0034] Component improvements: Leakage resistors R12 and R13 are selected as low-temperature drift metal film resistors (such as Vishay PTF series), with a temperature drift coefficient ≤50ppm / ℃;

[0035] Structural design: The entire circuit board is coated with conformal coating, and a heat shrink tubing is added between CX1 and D2 to prevent condensation from causing leakage.

[0036] Test results: After working continuously for 24 hours at -20℃, the output voltage fluctuation is ≤±2% and the leakage resistor value change is <1%.

[0037] Example 3: Long Lifetime Optimization Scheme

[0038] Capacitor selection: The filter capacitor C10 is a CBB film capacitor (such as the Kemet R46 series), with a capacitance of 100μF and a lifespan of >100,000 hours;

[0039] Relay optimization: The adjustable capacitor bank relay K1 is replaced with a solid-state relay (such as Panasonic AQV252G) to reduce mechanical wear;

[0040] Actual test data: Under high temperature of 85℃, the circuit runs continuously for 1000 hours, and the output voltage stability error is <±1.5%.

[0041] The above description is only a preferred embodiment of the present utility model. All equivalent changes and modifications made within the scope of the patent application of the present utility model shall be covered by the present utility model.

Claims

1. A resistive-capacitive step-down power supply circuit for heating intelligent toilet seats, characterized in that, The system includes the following modules: a step-down capacitor, a bleed resistor, a rectifier circuit, a voltage regulator, and a filter capacitor. The step-down capacitor is used to step down 220V AC to 5V DC. The bleed resistors R12 and R13 are connected in series and then in parallel across the step-down capacitor. The anode of the rectifier circuit is connected to the output terminal of the step-down capacitor, and the cathode outputs pulsating DC. The voltage regulator consists of a Zener diode D1 and a Zener diode D3 connected in parallel and a current-limiting resistor R1. The filter capacitor is connected in parallel to the output terminal of the voltage regulator.

2. The resistive-capacitive step-down power supply circuit for intelligent toilet seat heating according to claim 1, characterized in that: The surfaces of resistors R12 and R13 of the bleeder resistor are coated with conformal coating to meet the IPX4 protection level.

3. The resistive-capacitive step-down power supply circuit for intelligent toilet seat heating according to claim 1, characterized in that: The bleeder resistors R12 and R13 are connected in series and then in parallel across the step-down capacitor. When the power is off, the step-down capacitor discharges to prevent electric shock.

4. The resistive-capacitive step-down power supply circuit for intelligent toilet seat heating according to claim 1, characterized in that: The total resistance of the bleeder resistor is 1MΩ.

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