用220V直接给单片机供电。

jm***

liuzon*** 发表于 2024-9-9 11:09
These are made for the domestic electric bicycle charger, the production is very large, the profit ...

Be sure to tell the operator of this domestic electric bicycle charger, that you have decided he should end up paying far more in electricity costs over the life of this product, than you ever hoped to save in jellybean components !
Will he thank you ?

liuzon***

jm*** 发表于 2024-9-9 13:20
How does that reduce power consumption ?

If your pulse 10x the current for 10% of the time, your ...

You are right, the heat is not reduced. Still so much.After much thinking, I finaly like the first solution，it is simple, lowest cost.I also thought of using six Schottky voltage diodes in series, but the heat is not reduced. Or don't use it.

liuzon***

jm*** 发表于 2024-9-9 13:29
Be sure to tell the operator of this domestic electric bicycle charger, that you have decided he  ...

His charger is 1000w, and the whole charger I designed doesn't consume much power. It's much more efficient than the original transformer. I will switched to the main power, here 6 resistor  only consumes 5 mA,Power is less than 1 watt.

Tui***

liuzon*** 发表于 2024-9-9 11:49
用尽量低的成本生产充电器。

生产充电器？移动的？如果是这样，就更不能使用非隔离式降压方案，很容易出安全问题，安全隐患特别大。你能保证每一个元器件不被短路？断路还好，要是短路了呢？如果是自己搞研究可以，但真的不建议生产产品投放市场！

jm***

liuzon*** 发表于 2024-9-9 14:41
His charger is 1000w, and the whole charger I designed doesn't consume much power. It's much more  ...

I will switched to the main power, here 6 resistor only consumes 5 mA,Power is less than 1 watt.

Switch to pulsed DC  / full wave rectified mains does lower the power, but Spice shows it only lowers 3.6 watts to 2.7 watts (~75%)  for the same 10.5mA average load current.

That is why lowering the MCU current is so important.

liuzon***

Tui*** 发表于 2024-9-9 22:20
生产充电器？移动的？如果是这样，就更不能使用非隔离式降压方案，很容易出安全问题，安全隐患特别大。你 ...

任何低压电器总有热端和冷端，我这是在热端的。

liuzon***

jm*** 发表于 2024-9-10 07:54
Switch to pulsed DC  / full wave rectified mains does lower the power, but Spice shows it only l ...

对啊，电流的平方根热量正相关，电流降低一半，热量降低到四分之一。stc官方的数据是10ma。

hai***

都卷到这种程度了吗？我要是按你这样做，利润起码翻三倍

jm***

,Liuzonggong published on 2024-9-10 09:33
Yes, the square root of the current is positively correlated with the heat. If the current is reduced by half, the heat will be reduced to a quarter. The official data of STC is 10ma . ...

10mA can change with MHz.
STC8H series STC gives Inor = 1.49mA typ at 6MHz, and Iidle = 0.88mA at 6MHz
You also need to measure the Idd profile during startup , as that is not defined in the data sheet.


Other 50uA Iz operating zeners, to save energy on mains-dropper designs, are MMSZ4690 (5v6) and MMSZ4688(4v7) in SOD123 packages.


If you really do need 10mA and above, to power a MCU, there are pulsed mains dropper regulators like DK5030, or EC5230, which give inductor-less 5V at 30mA




These parts have 650V MOSFET and LDO, and turn ON the mosfet for AC between 8-45V then disable for the peak, and turn on again when AC drops 45-8V
VDD has a ripple supply,   6.5-7.5V and VOUT is a regulated DC

liuzon***

hai*** 发表于 2024-9-10 09:39
都卷到这种程度了吗？我要是按你这样做，利润起码翻三倍

看来你的利润厚啊，电动车充电器，出货量大，利润薄。只有一两块利润。