A converter is an electrical device that changes the voltage, frequency, number of phases, and other electrical quantities or characteristics of a power system. In addition to the main circuit (including rectifier circuit, inverter circuit, AC conversion circuit, and DC conversion circuit), the inverter also needs a trigger circuit (also known as a drive circuit) to control the on-off of power switching components and a control circuit to achieve energy regulation and control. The trigger circuit of the inverter includes two parts: a pulse generator and a pulse output device. The former generates pulses of a certain frequency, width, or phase according to the requirements of the control signal; The latter amplifies the level of this pulse into a driving signal suitable for the power switching components in the converter. Trigger circuits can be divided into phase controlled trigger circuits (used for controllable rectifiers, AC voltage regulators, direct frequency reducers, and active inverters), chopper controlled trigger circuits, and frequency controlled trigger circuits according to their control functions. The frequency control circuit using sine waves can not only control the output voltage of the inverter, but also improve the quality of the output voltage. The control circuit of the inverter is divided into loop control circuit and closed-loop control circuit according to the control method. The former is mainly used for some specialized equipment with low requirements; The latter has the function of automatic control and adjustment, and is widely used in various working machinery. According to the nature of control signals, analog control circuits and digital control circuits are divided. The most commonly used analog signals are DC voltage and current, which are easy to process and transform using electrical methods; A digital signal is a set of signals with discrete values and discontinuous changes in information parameters. Digital control has high accuracy, but the circuit is complex and expensive. Therefore, the widely used digital analog hybrid control circuit is actually. In addition, the use of microcomputer control circuits also has many advantages
Function of testing report:
1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report
2. Online e-commerce platform entry: Quality inspection report recognized by major e-commerce platforms 3. Used as a sales report: issuing legally effective testing reports to make consumers more confident 4. Papers and research: Provide professional personalized testing needs 5. Judicial services: providing scientific, fair, and accurate testing data 6. Industrial problem diagnosis: Verify the troubleshooting and correction of industrial production problemsBaijian and testing process:
1. Telephone communication and confirmation of requirements
2. Recommend solutions and confirm quotations 3. Mail samples and arrange testing 4. Progress tracking and result feedback 5. Provide reports and after-sales service 6. If urgent or priority processing is requiredTesting and testing characteristics:
1. The testing industry is fully covered, meeting different testing needs
2. Fully cover the laboratory and allocate localized testing nearby3. Engineers provide one-on-one services to make testing more accurate
4. Free initial testing, with no testing fees charged
5. Self service order delivery for free on-site sampling
6. Short cycle, low cost, and attentive service 7. Possess authoritative qualifications such as CMA, CNAS, CAL, etc 8. The testing report is authoritative and effective, and is generally used in China