MULTILADER 3 - Page 1
Forum section: electronics / beginners

author: Johnny65
author_rank: Newbie
timestamp: June 28, 2013, 01:14:16 pm
content: Well i don't know if this is the right Place to ask this?I v got a Multilader 3 and a resistor is broken and i cant find any info on what resistor to Replace it with it.SpecsOutput power :6-8 NiCd (7,2 - 9,6 V)bis 800 mATX :8 NiCid (9,6 V) bis 250 mARX :4 - 5 NiCid (4,8 - 6 V)( bis 150mA250V /50Hz / 20 VAHere is ithttp://www.graupner.de/en/products/55b4ab53-8423-4916-905e-287143deb4f6/6427/product.aspx

author: alanb
author_rank: Frequent Contributor
timestamp: June 28, 2013, 01:25:58 pm
content: If you can see the original resistor you may be able to read the value from the colour code. To find out about the resistor colour code just Google the topic. In terms of the wattage rating the physical size will give an idea of the rating needed, alternatively this can be calculated by reference to its resistance and either the max current through it or the voltage drop across it.If the above can't be done please post a picture of the inside of the unit and I will try and help further.

author: Johnny65
author_rank: Newbie
timestamp: June 28, 2013, 01:35:36 pm
content: Well I cant

author: Johnny65
author_rank: Newbie
timestamp: June 28, 2013, 02:07:32 pm
content: Quote from: Johnny65 on June 28, 2013, 01:14:16 pmHere is the board

author: Kevin.D
author_rank: Frequent Contributor
timestamp: June 28, 2013, 04:23:21 pm
content: Sometimes you can get the value of a resistor thats badly burned and is open circuit by measuring half of it's value . If you remove some of the outer insulating coating with a fine file to expose the resistance spiral underneath (be carefull so you dont go to deep with the file and damage the spiral underneath) then you can measure the value of the good half of the resistor with one of your meter probes directly on the spiral .

author: alanb
author_rank: Frequent Contributor
timestamp: June 28, 2013, 04:32:55 pm
content: Judging by the other nearby resistors that are of a similar size they are for current sensing on the outputs. Sorry I can't tell the colour of the third band on the one with the two orange bands. If its silver the value would be .33 Ohms if its gold it would be 3.3 Ohms. The other one is 0.47 Ohms. These may give an indication of the order of magnitude of the faulty one, you could then try a similar value and do some measurements with it in.

author: Johnny65
author_rank: Newbie
timestamp: June 28, 2013, 04:56:12 pm
content: Well I get 3,9 ohm hm so 3,9*3,9=7,8 Ohm then

author: Kevin.D
author_rank: Frequent Contributor
timestamp: June 28, 2013, 05:18:15 pm
content: 3.9 ? is that measuring half of it ( try to estimate the centre as close as possible ) . If so yes then I would go for 8.2 thats your nearest e12 prefered value. Check resistor temp is ok when testing ,because the original resistor didn't just overheat for no reason there's was something else wrong most likely.

author: Johnny65
author_rank: Newbie
timestamp: June 28, 2013, 07:04:40 pm
content: well I cut in half and got this reading now from the Resistor 5,4 Ohm 5,4*2= 10,8

author: SeanB
author_rank: Super Contributor
timestamp: June 28, 2013, 07:45:52 pm
content: To read with better accuracy take some thin bare copper wire and wind a single turn around the middle of the resistor, then tighten it to firmly press to the film, then read from the one end to the middle. That way you get better contact more closely approximating the end cap crimped all around it. You probably have a 4R7 resistor there

author: Johnny65
author_rank: Newbie
timestamp: June 28, 2013, 07:59:37 pm
content: I fixed it I put a 5 ohm res to the circuit and now it has the correct Voltage