Atom Feed - Twisted Pear Audio Support - Topic:What is the transistor needed for on the OTTO board? - 20Twisted Pear Audio Support - Atom Feedurn:twistedpearaudio-com:AtomFeed:TwistedPearAudioSupport:Topic:WhatisthetransistorneededforontheOTTOboard?-20:1Copyright 2024 Twisted Pear Audio Support2024-03-28T18:02:06Zhttp://www.twistedpearaudio.com/forum/Images/YAFLogo.pngForum Adminhttp://www.twistedpearaudio.comfeedback@twistedpearaudio.comBrian Doneganhttp://www.twistedpearaudio.com/forum/profile/8-Brian-DoneganBrian Doneganhttp://www.twistedpearaudio.com/forum/profile/8-Brian-DoneganRuss Whitehttp://www.twistedpearaudio.com/forum/profile/9-Russ-WhiteNicMachttp://www.twistedpearaudio.com/forum/profile/734-NicMacBrian Doneganhttp://www.twistedpearaudio.com/forum/profile/8-Brian-DoneganNicMachttp://www.twistedpearaudio.com/forum/profile/734-NicMacYetAnotherForum.NETurn:twistedpearaudio-com:ftPosts:st1:meid3293:1What is the transistor needed for on the OTTO board?<table class="content postContainer_Alt" width="100%"><tr><td>Yes, the resistor is only for feeding the base of the transistor, not the relay, so if you are switching 5V directly, you don't need either the resistor or the transistor, but would need to add a little jumper on the board to get the 5V to the relay coil.<br /><br /></td></tr></table>2009-06-05T16:17:56-07:002009-06-05T16:17:56-07:00Brian Donegan<table class="content postContainer_Alt" width="100%"><tr><td>Yes, the resistor is only for feeding the base of the transistor, not the relay, so if you are switching 5V directly, you don't need either the resistor or the transistor, but would need to add a little jumper on the board to get the 5V to the relay coil.<br /><br /></td></tr></table>urn:twistedpearaudio-com:ftPosts:st1:meid3290:1What is the transistor needed for on the OTTO board?<table class="content postContainer" width="100%"><tr><td>Yes. Just connect the supply. :)</td></tr></table>2009-06-05T16:16:13-07:002009-06-05T16:16:13-07:00Russ White<table class="content postContainer" width="100%"><tr><td>Yes. Just connect the supply. :)</td></tr></table>urn:twistedpearaudio-com:ftPosts:st1:meid3289:1What is the transistor needed for on the OTTO board?<table class="content postContainer_Alt" width="100%"><tr><td>Thanks Brian,<br /><br />Now I understand (at least I think so....) and look even more forward to AC1!<br />According to the data sheet the coil resistance of the relay in question is 69R. With 5V this yields 72.5 mA (the figures you indicated......).<br />If I'm not to stupid this means that I can use this relay with a switch and a 5V source without the need for a current limiting resistor. Correct? <br />Is this generally true for relays (i.e. that a current limiting resistor is not needed)?<br />A yes/yes answer would be comforting.<br /><br />Thanks again,<br />Nic<br /><br />P.S. With a retail price in Europe of around 15 euro (about 20$) for the relay alone your OTTO is a real bargain!!<br /><br /></td></tr></table>2009-06-05T15:42:08-07:002009-06-05T15:42:08-07:00NicMac<table class="content postContainer_Alt" width="100%"><tr><td>Thanks Brian,<br /><br />Now I understand (at least I think so....) and look even more forward to AC1!<br />According to the data sheet the coil resistance of the relay in question is 69R. With 5V this yields 72.5 mA (the figures you indicated......).<br />If I'm not to stupid this means that I can use this relay with a switch and a 5V source without the need for a current limiting resistor. Correct? <br />Is this generally true for relays (i.e. that a current limiting resistor is not needed)?<br />A yes/yes answer would be comforting.<br /><br />Thanks again,<br />Nic<br /><br />P.S. With a retail price in Europe of around 15 euro (about 20$) for the relay alone your OTTO is a real bargain!!<br /><br /></td></tr></table>urn:twistedpearaudio-com:ftPosts:st1:meid3287:1What is the transistor needed for on the OTTO board?<table class="content postContainer" width="100%"><tr><td>To energize the coil on the relay of the OTTO, you need to provide 72.5mA @ 5VDC. The reason the OTTO has the TR input and transistor is to allow a uC or other logic level device to trigger it. Most cannot supply enough current, so we added the transistor to act as a switch to deliver full current from the supply powering the OTTO. The resistor is to limit current delivered to the base of the transistor.</td></tr></table>2009-06-05T14:34:38-07:002009-06-05T14:34:38-07:00Brian Donegan<table class="content postContainer" width="100%"><tr><td>To energize the coil on the relay of the OTTO, you need to provide 72.5mA @ 5VDC. The reason the OTTO has the TR input and transistor is to allow a uC or other logic level device to trigger it. Most cannot supply enough current, so we added the transistor to act as a switch to deliver full current from the supply powering the OTTO. The resistor is to limit current delivered to the base of the transistor.</td></tr></table>urn:twistedpearaudio-com:ftPosts:st1:meid3285:1What is the transistor needed for on the OTTO board?<table class="content postContainer_Alt" width="100%"><tr><td>Hi,<br />On a hobby basis I'm trying to figure out how electronics works<img src="/forum/Images/Emoticons/eusa_doh.gif" alt="d'oh!" /> <br />I'm doing this by buying a lot of kits (a real TPAddict as measured by the hight of boxes I have accumulated!!!), assembling them, and trying to understand how they work<img src="/forum/Images/Emoticons/eusa_think.gif" alt="Think" /> <br />I must be very dumb because I cannot even understand what the transistor is doing on the OTTO board.... Somebody please enlighten me<img src="/forum/Images/Emoticons/eusa_pray.gif" alt="Pray" /> <br /><br />Thanks,<br />Nic<br /><br />P.S. I hope that Brian's moving is over and that: AC1, Ballsie Lite, Placid will be available soon<img src="/forum/Images/Emoticons/eusa_drool.gif" alt="Drool" /><br /><br /></td></tr></table>2009-06-05T13:28:58-07:002009-06-05T13:28:58-07:00NicMac<table class="content postContainer_Alt" width="100%"><tr><td>Hi,<br />On a hobby basis I'm trying to figure out how electronics works<img src="/forum/Images/Emoticons/eusa_doh.gif" alt="d'oh!" /> <br />I'm doing this by buying a lot of kits (a real TPAddict as measured by the hight of boxes I have accumulated!!!), assembling them, and trying to understand how they work<img src="/forum/Images/Emoticons/eusa_think.gif" alt="Think" /> <br />I must be very dumb because I cannot even understand what the transistor is doing on the OTTO board.... Somebody please enlighten me<img src="/forum/Images/Emoticons/eusa_pray.gif" alt="Pray" /> <br /><br />Thanks,<br />Nic<br /><br />P.S. I hope that Brian's moving is over and that: AC1, Ballsie Lite, Placid will be available soon<img src="/forum/Images/Emoticons/eusa_drool.gif" alt="Drool" /><br /><br /></td></tr></table>