C5ALIVE Forum

C5 Help => Components List => Topic started by: teamgardner on 21, May, 2012 - 21:30:49

Title: Replacement components?
Post by: teamgardner on 21, May, 2012 - 21:30:49
Hi, I replaced some components with some alternatives. So far everything sees okay so I thought I'd put them up.

ZD1 in control box replaced by BZY88C24

TR1 & 2 In the pod replaced by BC557

I am not experienced with electronics so if anyone spots a problem with these can they let me know.
Title: Re: Replacement components?
Post by: radiomarty on 21, May, 2012 - 22:12:59
Off the top of my head bud without looking up the data sheets - the originals were a matched pair of NPN and PNP transistors therefore replacing them with the same for tr1 and tr2 wont work - you need the matched opposite of the BC557  ie AN BC547 thus giving you a matched PNP AND NPN  pair - also need to check voltages and switching currents - PS I use the originals that are easily obtainable
Title: Re: Replacement components?
Post by: teamgardner on 21, May, 2012 - 22:44:57
Whoops! Glad you guys are here to help.
I couldnt find the originals anywhere. Do you you know where to get them from. I'd better swap them back
Title: Re: Replacement components?
Post by: radiomarty on 21, May, 2012 - 22:46:24
Search them on e-bay - always available on there - Marty :)
Title: Re: Replacement components?
Post by: teamgardner on 21, May, 2012 - 22:51:17
Thats where I've been looking. I just tried and still cant get anything. I'm searching for fst290
Title: Re: Replacement components?
Post by: marra on 21, May, 2012 - 22:53:45
Search them on e-bay - always available on there - Marty :)

hi marty, could you give a link(s) please. thanks m
Title: Re: Replacement components?
Post by: radiomarty on 21, May, 2012 - 23:00:49
OPPS - JUST REALISED YOUR TALKING ABOUT THE POD NOT CONTROL BOX DOOOOOOOOOOOOOOOOOOOH
Title: Re: Replacement components?
Post by: teamgardner on 21, May, 2012 - 23:04:20
You had me worried there. I thought I was going daft.
Title: Re: Replacement components?
Post by: radiomarty on 21, May, 2012 - 23:06:21
In that case i think they are suitable thanks for sharing them and sorry about my senior moment - i need some sleep !!!!!
Title: Re: Replacement components?
Post by: KarlG on 24, September, 2012 - 22:52:03
Hi teamgardner,

Quote
TR1 & 2 In the pod replaced by BC557

I recommend that you change 'BC557' to 'BC557C'.  This is the transistor that Phil quoted.

The reason for this is the parameters for the 557 are not the same as a 557C.

The gain (hfe), or the amplification, are not the same. Check the following:

BC557    minimum gain is 125
BC557B       "           "    "  220
BC557C       "           "    "  420

In a worst case scenario you fit a 557 that has the min. gain you could end up with the system not working correctly.

Regards.

KarlG.


Title: Re: Replacement components?
Post by: teamgardner on 27, September, 2012 - 12:14:08
thanks Karl. I have had no problems with the pod but if i do get problems now i will know why.