Will all or any battery charger ICs operate properly with rectified AC input?

[Andrew Lohmann]

Will all or any battery charger ICs such as L6924U operate properly with rectified AC input?

The rough circuit below is of a bicycle dynamo that delivers 300mA-500mA of varying AC frequency and current ripple will this prevent the charger controller from working properly?

https://photos.app.goo.gl/7W1iKxkfDLhZqULw6

[Peter BENSCH · Accepted solution]

In principle, nothing speaks against operating the L6924U or L6924D in this way.

However, you must pay attention to the maximum input voltage of 16V, since bicycle dynamos are more power current sources than voltage sources and can generate very high voltages when running without or very small load.

Regards

/Peter

[Andrew Lohmann]

Thanks possibly the circuit is not visible but it does have voltage limiting that you advise. I suspect the your answer will be true of many similar ICs including others made by other manufacturers but the detail is not clear.

[Peter BENSCH]

The voltage limiter with a crowbar is clearly visible - but it takes a TRIAC some time to fire. The max rating of 16V is the absolute maximum, i.e. even short-term and slight exceeding can damage the device. You could consider adding a TVS diode behind the Schottky full bridge rectifier, e.g. the SMBJ13A.