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[#1] Ac motor contorller Do any one know how to DIY ?? |
samsa2 正式會員 14.xxx.xxx.2 |
2022-08-15 13:07 | |
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[#2] Ac motor contorller 成品四處都可以買到,還非常便宜,個人認為DIY的意義不大。 |
羅密歐 會員 218.xxx.xxx.150 |
2022-08-15 13:52 |
[#3] Ac motor contorller 相信和Dimmer一樣 |
rcywong 正式會員 219.xxx.xxx.61 |
2022-08-15 14:07 |
[#4] Ac motor contorller There is bit different from original circuit. This is the speed control board, but i found that the speed is slower than normal (onlu 32rpm)any clue which parts in the circuit got faulty ? ( can exclude the belt and motor issue. I confirm they work well) 最後修改時間: 2022-08-15 17:35:18 |
Samsa2 正式會員 14.xxx.xxx.123 |
2022-08-15 17:32 |
[#5] Ac motor contorller i have some vintage table from lenco, thorens, Elac , use synchronous motor for 50 hz without the need of a controller..ran slow...29 rpm..30...etc ..belt / idler etc...motor all fine... after some good cleaning with correct lubricate..they back to 33.33...and clean all contact surfaces..etc.. if it is not lub and cleanliness of the bearing and contact surfaces ..., then it is likely some components issue at the board.. do u have the services manual of that table ? good luck.............. wish it is just bearing cleanliness issue first check.... clean those VR.. if it has one... if u have scpoe etc... u should able to check the wave front of the controller output..etc..if the output have correct timing = mechanical issue if not, it can be the VR, ...the Cap...etc.. may not be the the Transistor...but ..never know.. 最後修改時間: 2022-08-15 18:14:05 |
hahayanyan 正式會員 182.xxx.xxx.137 |
2022-08-15 18:09 |
[#6] Ac motor contorller Just wander what is the reading of correct waveform ? My motor states 16vac, 2VA 300ot/min |
Samsa2 正式會員 14.xxx.xxx.123 |
2022-08-15 18:33 |
[#7] Ac motor contorller cannot assume the motor must take 16VAC by the design to run at 33.33, as it can be 12Vac is needed or 15V etc even it is likely etc... however it is not the motor spec we are looking for, it is the "output of the controller" , that information we are looking for... may be for that motor... the output of the controller. it may be a 600 hz Sine Wave at 15+/- 1V.... etc..,. this is why..we need to have a service manual of the table... 最後修改時間: 2022-08-15 18:52:57 |
hahayanyan 正式會員 182.xxx.xxx.137 |
2022-08-15 18:51 |
[#8] Ac motor contorller This is the way of Pro-ject turntable that adopted microcontroller and wave shaping component to drive synchronous ac motor directly. |
LaLaLam 會員 42.xxx.xxx.160 |
2022-08-15 18:58 |
[#9] Ac motor contorller #1, Please refer below link to check MCU's voltage first: https://obsoletetechnology.wordpress.com/repairs/pro-ject-debutiii-repair/ |
LaLaLam 會員 42.xxx.xxx.160 |
2022-08-15 19:23 |
[#10] Ac motor contorller #8 this is really good reference, thanks! It says the problem is those input cap, do you know what role they play in the circuit ? Suppose frequency is not affected by voltage ? |
Samsa2 正式會員 14.xxx.xxx.123 |
2022-08-15 20:16 |
[#11] Ac motor contorller The reference case shown their issue was caused by two bad capacitors for the power supply (5vdc) of the mcu. Therfore their mcu was not working normally caused irregular speed. However, your case may be different. It's always true to measure the Vcc GND first, that's normally 5Vdc. Then, check the crystal frequency and MCU's divided frequency... etc., suppose if you have appropriate instruments. |
LaLaLam 會員 42.xxx.xxx.160 |
2022-08-15 21:09 |
[#12] Ac motor contorller Just checked the Vcc Gnd, its 5Vdc. I dont have instruments to check the frequency, its good to replace the crystal in this case ? |
Samsa2 正式會員 14.xxx.xxx.123 |
2022-08-15 22:27 |
[#13] Ac motor contorller You can replace the crystal for test but before doing so, you can remove the small capacitor (~30pF) to check if the frequency/speed is changed. Another possibility is that the load/torque/speed characteristic of the sync motor was changed due to aging. So, try to clean and lubricate the motor's moving parts may be helpful. |
LaLaLam 會員 42.xxx.xxx.160 |
2022-08-16 07:56 |
[#14] Ac motor contorller Thanks for the advice, i’ll try. Is it possible to modify or add some components to the circuit so that the frequency could be micro adjusted ? Btw do you know the model or spec of the crystal? |
Samsa2 正式會員 14.xxx.xxx.177 |
2022-08-16 09:46 |
[#15] Ac motor contorller Some design use variable capacitor to trim the crystal oscillator's frequency, but the trim range is in ppm only, (see below) may not suit your case. Your crystal frequency is 23062.5 Mhz, that is a tailor made one, may not be obtained easily in the market. |
LaLaLam 會員 42.xxx.xxx.160 |
2022-08-16 10:33 |
[#16] Ac motor contorller The variation from 33 to 32, may be mechanical related Wished u had triple check.. Ageing cap may affect it too, may not be the Crystal... |
hahayanyan 正式會員 121.xxx.xxx.161 |
2022-08-16 12:42 |
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