Differences

This shows you the differences between two versions of the page.

--- en:netzer:dimmer [2014/01/04 18:30] – svesch
+++ en:netzer:dimmer [2025/06/11 20:42] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
+====== 230 V Dimmer ======
+<note important>For this functionality the **[[io_project|IO project]]** (base or pro) has to be  [[fwupdates|uploaded]] to Netzer.</note>
+The Netzer supports the direct connection of phase dimmers. So it is possible to control high voltage loads like bulbs via Ethernet resp. Intranet/Internet.
+<WRAP center round important 60%>
+**Be careful when experimenting with 230 V. There is danger to life!**
+</WRAP>
+A phase switching mechanism is described here that is for example built up by a thyristor. For this switching mechanism, the important feature of the thyristor is that in zero crossing it deletes from mains voltage itself, i.e. switches off.
+{{ :phase_control.jpg?nolink& |}}
+The switching mechanism basically consists of zero-crossing detectors and a dimmer circuit.
+{{ :en:netzer:phasecontrol.gif?nolink& | Block diagram phase dimmer}}
+===== Zero-crossing detector =====
+IO0 is used as a zero-crossing detector for the 50\ Hz network frequency. For this purpose, the pin is required to be configured as a digital input with an edge trigger switched on:
+{{ :en:netzer:phasecontrolio0.gif?nolink& | IO0 setting}}
+Zero crossings must be captured by an external circuit, creating a homopolar pulse during every zero crossing. For this purpose, for example an AC optocoupler such as SFH620 is suitable.
+===== Dimmer circuit =====
+A triggered pulse output of Netzer is dimmed. **IO3** or **SPI_INT** are both suitable for this. It is hence possible to operate up to two dimmers in parallel.
+{{ :en:netzer:phasecontrolpulsee.gif?nolink& | Pulse setting}}
+This setting allows very granular gradations with a resolution of 200\ ns. Since under mains voltage a half cycle is 10\ ms and values between 100 (the is the smallest possible value in [[en:netzer:io#impuls|pulse operation]] and 50000 possible. Values comply with the time according **to which** the thyristor is powered. I.e. the larger the value, the less power will run at the output.