Electric hand tool motor power and control system based on step-down transformer output selection via relays.

Abstract

The invention relates to a power and control system that enables digital control of the speed, operating direction, and rotation direction of DC motors used in power tools. The system comprises a step-down transformer providing different alternating voltage levels, a relay group for selecting transformer steps, a rectification and filtering circuit, a semiconductor power stage for adjusting motor voltage, a control unit, a user interface, current and voltage measurement circuits, and safety units. The control unit selects the appropriate transformer step according to the required operating level, regulates the motor voltage, and performs operations such as stopping the motor during direction changes, switching the relays in a safe sequence, and restarting the motor. This provides stepped and safe motor control with low electrical noise, without the need for high-frequency motor power switching.

Description

1 TARIFF MULTI-STAGE TRANSFORMER, WITH SAFE STAGE SWITCHING AND LINEAR OUTPUT ADAPTIVE DC MOTOR POWER SUPPLY SYSTEM AND CONTROL METHOD Technical Area 5 The invention is an adjustable transformer that provides different alternating voltage levels. It relates to direct current motor systems. Specifically, the invention relates to the motor with a selected transformer stage. Step changes that adapt to the required output voltage and measured operating conditions. preventing simultaneous step connection during operation and a linear motor with low electrical noise. It relates to the power and control system supplying power from the output stage. 10 State of the Art In adjustable DC motor supplies, a linear connection of constant high DC voltage is achieved. It is known that the output voltages are reduced to low levels using a regulator. In this structure, the input and output The difference between the voltages is converted into heat on the series connection element; especially in low-power motors. Power loss and cooling requirements increase at higher voltages. Switched-mode converters 15 Switching components that can be moved to the motor terminals can increase efficiency. It is not preferred in every application due to its electromagnetic interference and acoustic behavior. For pre-regulation of a multi-stage transformer in front of a linear regulator. Switching is also known. For example, document US4733158A, according to line and load conditions. It describes a configuration that selects the transformer stage and feeds a linear regulator. With this, 20 together, creating a work allowance window dependent on an adjustable motor output command, The residual voltage in the energy storage element also increases during the transition from a high to a low stage. monitoring, implementation of different safe transition sequences for raising and lowering directions, single- Simultaneous execution of step-activated lock verification and transition of linear motor output. An additional solution for the combination of controlled suppression and subsequent re-raising throughout is 25. There is a need. Purpose of the Invention The aim of the invention is to maintain the linear output characteristic at the motor terminals while improving the linear power stage. reducing unnecessary voltage difference, overlapping of transformer windings by tap switches To prevent short circuits, the remaining energy in the energy storage element is reduced by 30 steps. 2 during which the effect on the motor output is controlled and managed by temperature, current or switching. The goal is to bring the engine to a safe state in case of incompatibility. For this purpose, the difference between the required output voltage for the motor and the rectified input voltage... The work allowance is monitored; the lowest suitable amount that provides the required work allowance under load is selected. The transformer stage is being selected; the stage change allows for a controlled increase in motor output. reduction or temporary blocking, opening of the effective stage, open status verification, dead time implementation, target level binding, single-level-effective by verifying the status and bringing the motor output back via ramp is being carried out. Figure Explanation 10 Figure 1 shows the main power and control architecture of the system. Figure 2: Multi-stage transformer, single-select tap switching unit, common rectifier, It shows the connection between the energy storage element and the linear output stage. Figure 3: Controller with voltage, current, temperature, stepper driver and output activation units. It shows the feedback relationship between them. 15 Figure 4 shows the flowchart applied for level selection and safe level transition. Explanation of References in Figures Reference Explanation Multistage isolated transformer 11 Common secondary terminals 12a-12e Secondary stage terminals providing different alternating voltages. Level selection unit 21a-21e Step switches 22 Key driver unit containing single-stage-active lock. 23 Key status feedback 24 Selected alternating voltage common line Rectifier unit 40 DC power storage units 41 Storage voltage measuring unit 3 Reference Explanation 50 Adjustable linear output units 51 Adjustable linear regulator 52 Series power transfer element 53 Power stage temperature sensor 54 Linear output activation or deactivation unit 60 DC motor or DC load 61 Motor current measuring unit 62 Motor output voltage measuring unit 70 Programmable controllers 71 Output voltage command unit 72 Event and fault log memory 73 Communication units 80 Auxiliary low voltage power supply unit 90 Main safety cut-off unit 101 Reading the Exit Command 102 Measurement of voltage, current and temperature 103 Calculation of candidate levels 104. Decision to change ranks 105 Reducing or suppressing motor output 106 Opening of the active level and verification of the open status 107 Expecting dead time and tension conditions 108 Connecting the target level and the single-level status. verification 109 Bringing back the linear output with a ramp 110 Safe shutdown in case of malfunction. Description of the Invention The system consists of at least three terminals (11) that provide a common secondary terminal and different alternating voltages. It contains an isolated multi-stage transformer (10) with a stage terminal (12a-12e). In the application example, the step voltages can be in the range of 0-12-18-24-30 / 32-36 VAC; however 4 The number of stages and voltages depend on the motor's nominal voltage, current, and desired output range. replaceable. Step terminals (12a-12e), selected alternative via step switches (21a-21e). The voltage is connected to the common line (24). Step switches (21a-21e) are electromechanical relays, solid state It may be a key or a combination thereof. The key driver unit (22) can have a maximum of 5 at any time. It implements a single-stage-active interlock that allows a single-stage switch to remain in conduction. Interlocking in the programmable controller (70), in the independent logic circuit or both realizable. The selected alternating voltage common line (24) is connected to the rectifier unit (30). Preferred In practice, a single full-wave bridge rectifier is used after all stages. Rectifier 10 The energy storage unit (40) connected to its output contains one or more electrolytic capacitors. This direct voltage of the energy storage unit (40) in the layout, diodes of the rectifier unit (30) It is disconnected from the alternating voltage line selected by the system. In an alternating application, the stages belong to the... Separate alignment elements can also be used. The output of the energy storage unit (40) is given to the adjustable linear output unit (50). Linear output 15 The unit (50) includes the adjustable linear regulator (51) and the series power switching element (52). In practice, the adjustable linear regulator (51) is a three-terminal regulator with high input voltage resistance. The adjustable regulator, series power switching element (52) is an NPN Darlington power transistor. Instead, linear regulators, bipolar transistors, MOSFETs, or parallel circuits can provide the same function. Power element structures can be used. 20 Output voltage command unit (71), from the user interface or another control system It transmits the received motor voltage demand to the programmable controller (70). The command unit (71), digital-to-analog converter, filtered pulse width modulation, digital potentiometer or it could be a galvanically isolated analog control circuit. Motor power current switched. Instead of being arranged as such, it is passed through the linear output unit (50) and the 25 at the motor terminals Switching components are reduced. Storage voltage measuring unit (41), motor current measuring unit (61), motor output voltage measuring unit The unit (62) and the power stage temperature sensor (53) provide measurement to the programmable controller (70). Measuring units include resistance dividers, current sensors, current shunts, thermistors, thermostats, or It can be formed from combinations of these. 30 The programmable controller (70) sets the required motor output voltage to V_TAL, energy storage The unit evaluates the voltage as V_DC and the motor output voltage as V_OUT. Linear output. The operating allowance of the unit is determined by the relation H=V_DC-V_OUT. Under load, the controller uses V_TAL. the lowest suitable transformer that provides the minimum working head required to generate the voltage The system selects the level as the candidate level. Minimum and maximum workload thresholds; motor current, power. Considering solid temperature, grid variation, rectifier drops, and measured voltage ripple. They can be determined in a fixed or adaptable manner by taking them into account. 5 To prevent step oscillation, hysteresis between raising and lowering thresholds is used sequentially. A minimum waiting period is applied between changes and a time filter is applied to measurements. One stage, only the lower stage motor voltage cannot be met with the required operating allowance It is upgraded once verified. Downgrading, on the other hand, is done because the lower level is not sufficient under load. and the residual voltage in the energy storage unit (40) will transition to the target level 10 It hinges on verifying that it remains within the expected voltage range throughout. Programmable controller (70), linear output activation unit (54) when switching to higher level It reduces or temporarily suppresses the motor output; activates the active stage switch; status feedback (23) confirms that the switch is turned on by voltage measurement or time model; Applies the specified dead time; disables the target high-level switch; target 15 only This confirms that the switch is active; the motor starts after the energy storage voltage stabilizes. It restores the output to the old command value using a ramp. When switching to the low level, the programmable controller (70) reduces or suppresses the motor output; Active high-level switch is activated; verifies all level switches are open; dead It completes the time condition and closes the target low-level switch. Rectifier unit (30), 20 It separates the high residual voltage of the energy storage unit (40) from the low-stage winding. The controller determines that the energy storage voltage matches the expected voltage envelope for the target low-stage. It monitors the input; verifies the single-stage-active status; and returns the motor output via ramp. In the alternative application, the target is connecting the low-stage voltage, which is now at the specified threshold. It can be conditional on landing. 25 Key status feedback (23) from the auxiliary contacts of the relays, separate contact obtained from sensors or from comparing expected and measured V_DC values It is possible. Simultaneous activation of multiple stages, occurrence of off-target voltage, and excessive voltage may occur. Main safety in case of current, excessive temperature, measurement inconsistency or controller communication loss. The cutting unit (90) cuts off the motor power. Main safety cutting unit (90), main relay, thermal switch, 30 It can consist of a fuse, an electronic circuit breaker, or a combination of both. 6 Event and fault log memory (72), stage change times, voltage and current values, It can store temperatures, relay mismatches and reasons for shutdown. Communication unit (73) This information can be transmitted to the user interface or remote monitoring system. Auxiliary low voltage. The motor supply unit (80), auxiliary loads such as relays, controller, display, fans and lighting. It can supply power independently of the power path or with a common reference. 5 In one application example, the system continuously operates between 0 V or approximately 6 V and approximately 33 V. Provides adjustable motor output. Voltage ranges, motor power, transformer stages and The work margin thresholds can be differentiated in a way that does not limit the scope of the invention. How the invention can be applied to industry. The invention relates to dental or manicure milling machines, laboratory motors, precision DC machines, silent 10 fan and pump drivers requiring adjustable DC with low electrical noise It is applicable in devices. The system includes a power board, motor control board, and programmable control. It can be produced modularly as a unit, or as a single printed circuit board or a group of multiple printed circuit boards. It can also be produced in this form.

Claims

1 REQUESTS 1. The invention involves generating adjustable direct current motor voltage by converting different alternating voltages to produce a direct current motor voltage. multi-level terminals (12a-12e) with a common secondary terminal (11) providing step transformer (10), select one of the step terminals alternating voltage common Step selection unit (20) connecting to line (24), rectifier unit (30), direct voltage energy 5 storage unit (40), adjustable linear output unit (50), motor output voltage command unit (71), measuring units measuring at least storage voltage and motor output voltage (41, 62) and The feature of the DC motor supply system is that it includes a programmable controller (70); The programmable controller (70) measures the requested motor output voltage and storage. The minimum suitable 10 that will keep the linear operating range between the voltages between a lower and an upper threshold. Determining the step terminal, reducing the linear output at any step change, or suppression, activating the active stage switch, a dead zone where all stage switches are open. Time application, connecting the target level switch, only one level at a time by verifying that the switch is active and bringing the linear output to the command value via ramp. together, during the transition from high to low stage, the energy storage unit (40) is now 15 By monitoring the voltage, the connection time of the target low stage or the re-entry of the linear output can be determined. It determines the activation time.

2. According to claim 1, it is a direct current motor supply system and its feature is; step selection unit (20), electromechanical relay, solid-state switch, or a combination thereof, and switch driver. The step switches (21a-21e) are driven by unit (22) to be single-stage-active. It includes.

3. DC motor power supply system according to claim 1 or 2, characterized by its step size. a common selected alternative after the step selection unit (20) of terminals (12a-12e) the joining of the voltage line (24) and the said common line to a single full-wave bridge rectifier It is connected to the unit (30). 25 4. A DC motor power supply system that meets any of the above requirements and has the following characteristics: adjustable linear output unit (50), adjustable linear regulator (51) and this regulator It contains at least one series power transfer element (52) controlled by.

5. A DC motor power supply system that meets any of the above requirements and has the following characteristics: The programmable controller (70) candidate stage is taken from the motor current measuring unit (61) 30 2 current and power based on at least one of the temperature values ​​received from the stage temperature sensor (53). It is an adaptation.

6. A DC motor power supply system that meets any of the above requirements and has the following characteristics: different upgrade and downgrade levels that prevent successive level changes It must include at least one of the following: thresholds, minimum step waiting time, and measurement time filter. 5 7. A DC motor power supply system that meets any of the above requirements and has the following characteristics: Reducing or suppressing the linear output when switching to a higher stage, activating the effective stage, Verification of open state, application of dead time, binding of target high level, single- Verification of the step-effective status, stabilization of the storage voltage. It is the process of waiting and then bringing the linear output back via ramp. 10 8. A DC motor power supply system that meets any of the above requirements and has the following characteristics: Reducing or suppressing the linear output during the transition to the low range, effectively reducing the high range. opening, verifying all level switches are open, target low level dead after the connection, the storage voltage is the expected voltage for the target low-stage. It involves monitoring its entry into the envelope and applying the sequence of returning the linear output via ramp. 15 9. A DC motor power supply system that meets any of the above requirements and has the following characteristics: key status feedback (23) relay auxiliary contact, separate contact sensor, selected from step voltage measurement or comparison of expected and measured storage voltages It is achieved with at least one of them.

10. A DC motor power supply system with the following characteristics according to any of the above requirements; 20 Simultaneous multi-stage activity, off-target voltage, overcurrent, overtemperature, measurement. If at least one of these is detected—either inconsistency or loss of controller communication—the main security The cutting unit (90) cuts off the motor power.

11. A DC motor power supply system that meets any of the above requirements and has the following characteristics: If the main safety cut-off unit (90) reaches the specified temperature of the power stage, the main relay 25 It contains a normally closed thermal switch that opens the coil circuit.

12. A DC motor power supply system that meets any of the above requirements and has the following characteristics: The event and fault log memory (72) records step changes, voltages, motor current, temperature and keeping the reason for the closure with time information and the communication unit (73) said information It is the transmission of information to a user interface. 30 3 13. The invention is a transformer (10) that provides different alternating voltage levels, with step selection. unit (20), rectifier unit (30), energy storage unit (40) and adjustable linear output unit (50) is the control method of the direct current motor supply system containing; its feature is the demanded Reading of motor output voltage (101), measurement of storage voltage and motor output voltage (102) linear operating margin between the requested voltage and the measured storage voltage is 5 Calculation of the lowest suitable level that fits between the determined lower and upper thresholds (103), Reducing or suppressing the linear output when a step change is required (105), effective step opening and verification of open status (106), dead time when all levels are open implementation (107), linking of the target level and verification of single-level-effective status (108) includes steps (109) of bringing the linear output to the command value with ramp and high 10 During the transition from a higher to a lower level, the energy storage unit's voltage is now monitored to target the voltage. low stage connection time or linear output re-enablement time It is the determination of.

14. This is a control method according to claim 13, and its characteristic is; candidate stage, motor current, power stage. 15 using at least one of the following: temperature, grid variation, and storage voltage fluctuation. This is calculated according to the defined adaptive workload thresholds.

15. Control method according to claim 13 or 14, characterized by: promotion and demotion. different thresholds for decisions, minimum step waiting time and measurement time filter It is the implementation.

16. Control method according to any of claims 13-15, and its characteristic is; step switch status 20 If the measured storage voltage does not match the expected step voltage, then all The process involves activating the step switches, suppressing the linear output, and creating a fault log.

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