Talabarin da Turbin Daingiyar Kirkiro na Tashin Bincike Ta Aikace MAX038 da BTL Amplification
1 Jamiyar Kudin Da Maimakawa
Wani abin da ya yi amfani da wuri mai yawa don kawo shiga maimakawa mai iya kusa da adadin lokaci da tushen lokaci. An samun maimakawa daga fagen bayanai da fagen tushen lokaci, maimakawa ta zama.
1.1 Wannan Mai Amfani Don Kawo Shiga Sine Wave Na Biyu Da Yawa Daga Bayanai
Fagen bayanai na sine wave yana cikin MAX038 wanda an samu shi daga MAXIM Corporation ta Amurka. Idan an bukata, wannan fagen bayanai yana bukatar 3 chips kuma zan iya kawo shiga kamar 3 channel sine signals. MAX038 yana cikin function generator mai inganci. Idan an gina fagen bayanai mai yawa (tambaya Figure 1) da kuma an kontrola pin A₀ da A₁ (tambaya Table 1), za a iya kawo shiga sine waves, rectangular waves, da triangular waves.
Kawo karfi adadin lokaci: Idan pin FADJ ta zama zero level, za a iya kula adadin lokaci na output tare da formula Fₐ = IIN / Cf(ida IIN= Vref/ Rin; Fₐ shine adadin lokaci na output, a MHz; Cf shine capacitance na fagen bayanai na oscillator, a pF; IIN shine current na output pin IN, a μA; Vref shine voltage na output pin REF; Rin shine resistance na input pin IN).
Kawo karfi duty cycle: Zan yi hanyar kananan pin DADJ don kawo karfi charging da discharging rates na capacitor Cf. Idan pin DADJ ta zama zero level, duty cycle yana zama 50%. Idan voltage na pin DADJ ta faru ne a cikin -2.3～2.3 V, duty cycle yana faru ne a cikin 85%～15%. Za a iya kula kawo karfi duty cycle tare da formula Vdadj =₋50%- DC×0.0575 (ida Vdadj shine voltage na pin DADJ).
1.2 Samun Output Orthogonal Ta Hanyar Single-phase, Three-phase, Da Two-phase
Phase detector na MAX038 zan iya amfani don gina fagen bayanai na phase-locked loop. Idan an kawo shiga rectangular wave signals na three-phase a terminal PDI na uku MAX038, za a iya kawo shiga sine wave signals na three-phase AC. Don single-phase signal output, za a iya rufe biyu sine wave generators, kuma akwai kawai wauci zai yi aiki.
Ba a bukata phase adjustment signals a PDI. Principle na two-phase orthogonal signal output ana iya sama da three-phase output. Idan an rufe wani sine wave signal generator, sannan an kawo shiga biyu orthogonal rectangular wave signals a terminal PDI na biyu sine wave signal generators, za a iya kawo shiga two-phase orthogonal AC signals. Wannan synchronization signal na rectangular external zan iya amfani don programmable PLD. Zan iya kawo shiga three-phase power-frequency square wave signal zuwa 6 states (tambaya Figure 2).
Za a iya iya cewa zaman lafiya daga wani state zuwa wani baki daya shine 3.3 ms (da period 20 ms a 50 Hz). Idan 6 output states sun faru ne masu 3.3 ms kuma sun faru ne tsakanin musamman, za a iya kawo shiga three-phase power-frequency square wave signal. Ana iya kula two-phase orthogonal signal da kuma kawo shiga zuwa 4 states (S₇, S₈, S₉, S₁₀). Zaman lafiya daga wani state zuwa wani baki daya shine 5 ms. Idan 4 output states sun faru ne masu 5 ms kuma sun faru ne tsakanin musamman, za a iya kawo shiga two-phase orthogonal square wave signal na power-frequency.
Waveform na phase synchronization control na MAX038 za a iya kawo shiga signals Q₂, Q₀, Q₁ daga pins 16#, 14#, and 13# na P16R6 programmable chip (tambaya data na P16R6) zuwa external synchronization signal terminals PDI na uku MAX038. An samun AND gate a output pin 13#, controlled by signal Q₃. Idan an edit program don Q₀, Q₁, Q₂, Q₃ suka ci gaba (Table 2), za a iya samun generation na three-phase and two-phase orthogonal rectangular external synchronization signals
1.3 Principle Na Implementation Power Amplification
Circuit na amplification na single-phase yana cikin Bridge-Tied Load (BTL) structure. Biyu ends na load suka faru ne a output terminals na biyu amplifiers. Output na wani amplifier yana mirror output na wani. Ya'ni, signals na biyu ends na load ba suka da farko lokacin mulkin 180°. Voltage na aka samu a load yana biyu original single-ended output voltage (tambaya Figure 3), ta haka yana tabbatar da single-phase output ba zai ƙarin 100 W.
2 Debugging Hardware Na Maimakawa Tester
2.1 Distortion Adjustment Na Output Waveform
Setting na duty cycle: Apply a voltage control signal ranging from -2.3V to +2.3V to the DADJ terminal of MAX038 to adjust the charging and discharging time of capacitor Cf. Adjust the triangular wave output by the oscillator within the range of 10% - 90%, and finally generate distorted sine waves, sawtooth waves, and pulse waves. Since a constant current of 250 μA flows into the DADJ terminal, connect a resistor Rd between this terminal and the reference power supply pin REF. Then: Vdadj = Vref - 0.25Rd; Adjusting the value of Rd can adjust the duty cycle of triangular waves and sawtooth waves without affecting the synchronous output pulses, and Rd should not be greater than 20 kΩ.
2.2 Frequency Adjustment Na Output Waveform
Output frequency na MAX038 tana kontrola don oscillation capacitor Cf, IIN current, and FADJ voltage. Idan Cf yana zama fix, fine frequency tuning zan iya samu hanyar kontrola pin IIN. Don digital control, DACs suka faru ne a IIN and FADJ. Su zan iya kawo shiga small voltages, converted to 0-748 μA current (plus 2 μA from the network) for 2-750 μA at IIN, creating the output frequency range. The DAC divides this range into 256 steps, enabling coarse adjustment via IIN current and fine tuning through the DAC.
2.3 Voltage Output Adjustment Na Power Amplification Circuit
The three single-phase step-up transformer circuits function as a three-phase transformer for simultaneous signal boosting (avoiding the significant impact of direct three-phase transformer use on small signals). Voltage adjustments between 200 V and 80 V are achieved by regulating the transformers.
2.4 DC Working Circuit Voltage Adjustment
A DC voltage transformation and stabilization circuit provides stable DC power from the on-site 220 V AC supply. It outputs +35 V and +5 V (meeting transformer precision requirements) using 7805 and 7905 DC power modules.
3 Conclusion
Maimakawa na samun clear functionality, cost-effectiveness, and high output precision, fully meeting testing instrument requirements.
Modular design reduces complexity, with interconnected yet independent circuits. Clear functional division (sine wave generation, phase control, power amplification, DC supply) allows continuous upgrades to meet user needs.
Control signals Q0-Q3 enable MCU compatibility and digital control. Combined with modular design, the device outputs three-phase, two-phase orthogonal, and single-frequency sine signals, plus rectangular/triangular waves with various phase requirements, satisfying diverse tasks.
