怎样用串口通信去控制伺服速度呢？RS-232通讯格式有哪几种？
2021-10-11 07:55
1.风速传感器原理--简介风速传感器主要采用的是优质铝合金型材，在表面进行电镀喷塑处理，它具有良好的防侵蚀，抗腐蚀特点，可以有效的保证长期使用的仪表不起锈，同时配合内部顺滑的轴承系统一起使用，确保了采集信息的准确性。风速传感器是一种使用方便，性能好，可靠性高的智能仪器仪表，可以广泛的用于测量温室，环保，气象站以及养殖等场所风速。
2020-08-14 06:57
D类放大器的基本原理是什么？D类放大器有哪些优点？D类放大器有哪些应用？
2021-04-21 06:30
差模电感(DM inductor)必须流过交流电源电流，一般是采用μ值较低的铁粉心(Iron powdercore)，由于μ值较低所以感值较低，典型值是数十uH 到数百uH 之间。
2019-10-08 14:28
怎么实现基于Hi3510的H.264编解码器的设计？
2021-06-04 06:15
嗨，我上周拿到了全新的34465A数字万用表，它已经由Keysight（初始/生产校准）6月1日校准。开箱即用，它有一个令人不安的高校准计数222.另一个新的34470A的所有者发现76卡路里计数，似乎也太高，可能高达20或40似乎是合理的，因为计数似乎增加了仅每个校准组1个。 （100V和500V DCV的校准仅增加1）我认为，是德科技目前在生产过程中最终校准这些仪器存在很大问题。我发现，使用ACAL后，DCV范围为100mV，1V和+/- 10V，并且始终为10GOhm。如果我切换到10MOhm，两个范围内的读数都会高出+ 3ppm，尽管不涉及硬件切换，因为HV范围已经处于10MOhm模式！如果我使用10MOhm设置进行校准，则验证也会失败+ 3ppm，切换到AUTO会消除此错误。这两个误差总计达到+17和+ 20ppm，这已经是90天的漂移。在Keysight校准过程中，由于ACAL可能在验证之前启用，这可能会导致校准错误，解释我的仪器的高222计数。其次，如果仪器已经以20ppm开始并且正常漂移将增加，那么该仪器将在90天或1年规格中失效。因此，我需要Keysight工程部门的支持，以获得对该错误的确认，以及固件或硬件中的修复，如果它证明与HW相关（我的理解可能性较小）。我还可以提供序列号，测试报告以及我自己测量的更多细节。关心弗兰克博士 以上来自于谷歌翻译 以下为原文Hi, I got my brand new 34465A DMM last week, it had been calibrated by Keysight (initial/ production calibration) June 1st. Out of the box, it had a disturbingly high calibration count of 222. Another owner of a new 34470A found 76 cal counts, which seems also too high, maybe up to 20 or 40 seems to be reasonable, as the count seems to increase by 1 per calibration group only. (calibraton of 100V and 500V DCV increases by 1 only) I assume, Keysight currently has big problems to finally calibrate these instruments in their production run. I found out, that the DCV ranges 100mV, 1V, and +/- 10V were spot on, after using ACAL, always 10GOhm). If I switch to 10MOhm, the reading is +3ppm higher in both ranges, although there is no hardware switching involved, as the HV ranges are already in this 10MOhm mode! If I calibrate with 10MOhm setting, the verification also fails by +3ppm, switching to AUTO removes this error. Both errors sum up to +17 and +20ppm, which already is the 90 day drift. During Keysights calibration process, as ACAL probably is engaged before verification, that will probably cause a calibration error, explaining the high 222 counts of my instrument. Secondly, this instrument will fail the 90 days or 1 year specification, if it already starts at 20ppm and the normal drifts will add to that. So I need support from Keysight engineering, to get a confirmation of that bug, and a fix in the firmware, or in hardware, if it turns out to be HW related (less probable to my understanding). I could also supply serial number, test report and further details of my own measurements. Regards Dr. Frank
2018-10-10 17:43
什么是数字视频监控系统？数字视频监控系统中的DVR技术有哪些？
2021-06-07 07:02
