{"id":7322,"date":"2023-05-12T09:53:06","date_gmt":"2023-05-12T07:53:06","guid":{"rendered":"https:\/\/wp.delphin.de\/?post_type=glossar&#038;p=7322"},"modified":"2026-06-24T12:49:20","modified_gmt":"2026-06-24T10:49:20","slug":"freewheeling-diode","status":"publish","type":"glossar","link":"https:\/\/www.delphin.de\/en\/glossar\/freilaufdiode\/","title":{"rendered":"Freewheeling diode"},"content":{"rendered":"<p class=\"wp-block-paragraph\">One <strong>Freewheeling diode<\/strong> is a protective diode used in electrical circuits to protect sensitive electronic components from dangerous voltage spikes. Such overvoltages occur in particular when switching off <strong>inductive loads<\/strong> such as relays, contactors, solenoid valves, or DC motors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Inductive loads contain coils that generate a magnetic field during operation. If the power supply is interrupted, this magnetic field collapses. Due to the physical property of the <strong>Self-induction<\/strong> However, the coil attempts to maintain the previous current flow. This can cause a high reverse voltage to build up within a very short time, which can damage electronic circuits, outputs, or switch contacts.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The free-wheeling diode is connected in parallel with the inductive load. During normal operation, it is in the reverse-biased state and has no effect on the circuit\u2019s operation. Only when the load is turned off does the resulting reverse voltage take effect. The diode turns on and provides a closed current path for the induced current, allowing the stored energy to be dissipated in a controlled manner.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This significantly reduces dangerous voltage spikes and reliably protects connected components.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Typical Applications of Free-Wheeling Diodes<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Relays and Contactors<\/li>\n\n\n\n<li>Solenoid Valves<\/li>\n\n\n\n<li>Electromagnets<\/li>\n\n\n\n<li>Direct-current motors<\/li>\n\n\n\n<li>PLC outputs<\/li>\n\n\n\n<li>Digital Outputs from Measurement and Automation Systems<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Advantages of Free-Wheeling Diodes<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Protection against induced overvoltages<\/li>\n\n\n\n<li>Extending the Service Life of Electronic Components<\/li>\n\n\n\n<li>Protection of Switching Contacts and Output Stages<\/li>\n\n\n\n<li>Reduction of Electromagnetic Interference<\/li>\n\n\n\n<li>A simple and cost-effective protective measure<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Importance in Measurement and Automation Technology<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Inductive loads are frequently switched in measurement, control, and automation systems. Without appropriate protective measures, the voltage spikes that occur during switch-off can damage outputs or cause malfunctions. The use of free-wheeling diodes is therefore one of the fundamental measures for ensuring reliable and long-lasting system operation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In particular, when using measurement and automation devices to control relays, valves, or contactors, free-wheeling diodes should always be taken into account to provide long-term protection for the electronics against overvoltage.<\/p>","protected":false},"featured_media":0,"template":"","class_list":["post-7322","glossar","type-glossar","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.delphin.de\/en\/wp-json\/wp\/v2\/glossar\/7322","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.delphin.de\/en\/wp-json\/wp\/v2\/glossar"}],"about":[{"href":"https:\/\/www.delphin.de\/en\/wp-json\/wp\/v2\/types\/glossar"}],"wp:attachment":[{"href":"https:\/\/www.delphin.de\/en\/wp-json\/wp\/v2\/media?parent=7322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}