Is this a strange sort of rectifier? - Page 1
Forum section: electronics / beginners

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 22, 2018, 08:21:49 pm
content: I found a schematic over something that, for me, looks like a strange rectifier.Am I right, if so what does it do more then a "standard" rectifier?

author: Ian.M
author_rank: Super Contributor
timestamp: May 22, 2018, 08:43:21 pm
content: There's nothing strange there - just a bridge rectifier with two loads - R1 and (R2 + L1). As there are no voltages or component values we don't have much else to go on, except C1 is polarised so may be a large electrolytic, so R1 may be a bleed resistor in case (R2 + L1) go open-circuit so its single fault fail-safe.

author: Gregg
author_rank: Super Contributor
timestamp: May 22, 2018, 08:49:58 pm
content: I believe it is the position of R1 on the schematic that is confusing you. Move it to the right of C1 and it is electrically the same but easily seen as a bleed resistor as Ian.M suggested.

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 22, 2018, 09:02:44 pm
content: Thanks but what are the purpose of the two bleed resistor and what about the inductor?

author: Ian.M
author_rank: Super Contributor
timestamp: May 22, 2018, 09:14:57 pm
content: I only see one bleed resistor. We have no idea why the original designer wanted to put a resistively limited current through that inductor. Possibly it's to provide a steady(ish) magnetic field.If you name the equipment and/or provide the full schematic you'll probably get better, more definite answers.

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 22, 2018, 09:30:07 pm
content: Unfortunately this all I found and I did do a lot of search to get some idea of it all, before asking here:-)Magnetism, Is that not something you should avoid?EDIT: Just found an other schematic where it says that R2 and L4 will convert the sinus curve to a square signal, if L4 is a lot larger then R2.Go down to: "With inductive (RL) Load" on this page:https://www.daenotes.com/electronics/devices-circuits/full-wave-bridge-rectifier

author: Zero999
author_rank: Super Contributor
timestamp: May 22, 2018, 10:13:09 pm
content: If R2 is the load, then the inductor would be acting as a filter, to reduce the current ripple, but such an arrangement would be unusual. Normally the inductor would come before the main filter capacitor.

author: High_vacuum_house
author_rank: Newbie
timestamp: May 22, 2018, 10:27:45 pm
content: Difficult to know what is going on here without some component values and expected voltages. If it was a power supply which is what I think the inductor would normally link between the bridge rectifier and the smoothing capacitors as an LC filter.The other option with the inductor is could it be the coil of a relay with the contacts not shown to indicate to something that the power supply is energised. R2 limiting the current being drawn in the relay coil?Christopher Capener

author: RoGeorge
author_rank: Super Contributor
timestamp: May 22, 2018, 10:41:43 pm
content: Quote from: FriedMule on May 22, 2018, 09:30:07 pmI looked only at the chapter "With inductive RL Load". All wrong.Stay away from that site.

author: FriedMule
author_rank: Frequent Contributor
timestamp: May 22, 2018, 10:58:06 pm
content: Thanks to your all! :-)It looks like I again have found something fishy or at least an explanation that comes straight out of a "expert" site:-)