Hi.
I have an automotive 12v 4 way accessory switch but unfortunately there was a short which took out the ability to individually switch off/on the 12v outputs. The 4 12v outputs are on permanently. I found that 3 of the 4 333200N transistors were damaged.
I can not find any reference to transistor 333200N to buy, or an alternative UK. Please can anyone help?
Thanks in advance.
Hi and Newbie Question 333200N Transistor
Re: Hi and Newbie Question 333200N Transistor
The number you quote may well be specific to the manufacturer of the switch, which is why you won't find it online or in catalogues. What you have to do is to find suitable retail replacements - not to difficult in non-critical applications. Have you any idea of the current which these transistors have to switch? is the load which is to be switched resistive (such as a bulb, heater, radio) or inductive (such as a motor)?
Look for a replacement which can carry at least the maximum current, with a good safety margin. As this is for use in cars you are not going to need a high voltage transistor. Use one which is of similar physical size as the damaged ones - tiny transistors may not be able to handle the heat dissipation. Also check all the other components around, especially if there is a diode connected across the load (evidence of an inductive load).
Hope this helps - long-distance servicing has to be general!
Look for a replacement which can carry at least the maximum current, with a good safety margin. As this is for use in cars you are not going to need a high voltage transistor. Use one which is of similar physical size as the damaged ones - tiny transistors may not be able to handle the heat dissipation. Also check all the other components around, especially if there is a diode connected across the load (evidence of an inductive load).
Hope this helps - long-distance servicing has to be general!
Re: Hi and Newbie Question 333200N Transistor
Hi David, and many thnks for reply.
I thought it may be the manufacturers own part no. I would not know what would be a suitable replacement for the 33300N though.
The unit is only to switch between 12v car accessories e.g. LEDS. There are 2 sets of transistors. One set is a PNP 30v, 25v, 6v 1.5A, and this 33300N 4 leg type.
I have included a picture below.
Any more advice on a suitable replacement would be very much appreciated.
I thought it may be the manufacturers own part no. I would not know what would be a suitable replacement for the 33300N though.
The unit is only to switch between 12v car accessories e.g. LEDS. There are 2 sets of transistors. One set is a PNP 30v, 25v, 6v 1.5A, and this 33300N 4 leg type.
I have included a picture below.
- car 4 way switch1.jpg (226.57 KiB) Viewed 7735 times
Re: Hi and Newbie Question 333200N Transistor
Oh! Thanks for the pic - much more info. 4-lead transistors do exist, but are uncommon. I am wondering if the 333200 devices are, in fact, rectifier bridges? Incidentally, have you checked that the relays (black cuboids at the bottom of the picture) are working correctly? Heavy currents, such as from short circuits can fuse the contacts together. You mentioned in your first post that three of the 333200 devices were damaged. How did you check them - they don't appear from the pic to be burnt or otherwise damaged.
Re: Hi and Newbie Question 333200N Transistor
David,
Yes a picture is worth a thousand words. I should've put in original post to save everyone's time D'oh!
I have checked the relays as you suggested, there is continuity beween these 2 connections on all 4 relays:
The top connection on the diagram is the 12v out. I am unsure if diagram showing energised or un-energised state. I don't know if when energised the contact is meant to be open, and the 4 way switch that connects to the 90 deg pins in previous photo when selected de-energises the relay.
Now you've pointed out it that the 333200N may be a rectifer it makes sense as it looks to be AC-DC rectifer bridge in conjuction with the relays. I assumed the 333200Ns were damaged due to what look like burn spots on the reverse side on 3 out of 4 of them:
I just need to replace them with something similar but have no idea of their specs.
Yes a picture is worth a thousand words. I should've put in original post to save everyone's time D'oh!
I have checked the relays as you suggested, there is continuity beween these 2 connections on all 4 relays:
- relay 1.jpg (43.75 KiB) Viewed 7726 times
Now you've pointed out it that the 333200N may be a rectifer it makes sense as it looks to be AC-DC rectifer bridge in conjuction with the relays. I assumed the 333200Ns were damaged due to what look like burn spots on the reverse side on 3 out of 4 of them:
- burnt1.jpg (216.13 KiB) Viewed 7726 times
Re: Hi and Newbie Question 333200N Transistor
A quick Google search for 333200N pulls up quite a few pages. Probably including some totally unconnected with electronics!
Yes, the three look quite ill!
I am unsure why you need bridge rectifiers in a car device - usually the only source of AC is the alternator. It might be to make some part of the circuitry polarity-independent. Have you any idea?
Relays are usually drawn and shown on schematics in their unenergised state. Apply 12Vdc to the coil terminals, and see if the relay switches.
Yes, the three look quite ill!
I am unsure why you need bridge rectifiers in a car device - usually the only source of AC is the alternator. It might be to make some part of the circuitry polarity-independent. Have you any idea?
Relays are usually drawn and shown on schematics in their unenergised state. Apply 12Vdc to the coil terminals, and see if the relay switches.
Re: Hi and Newbie Question 333200N Transistor
David, thanks for your time with replying.
I also can't work out why a bridge rectifier is needed. There is no AC, only the unregulated 12v associated with car accessory or live feeding this unit to power 12v accessories individually, controlled via a membrane type switch.
With respect to 333200N part number, if the number is rearranged to say 3N200, a Google search brings up a datasheet for a FET.
I will try energising relay to see if it's operational.
I would buy a new unit but they are not available anymore.
I also can't work out why a bridge rectifier is needed. There is no AC, only the unregulated 12v associated with car accessory or live feeding this unit to power 12v accessories individually, controlled via a membrane type switch.
With respect to 333200N part number, if the number is rearranged to say 3N200, a Google search brings up a datasheet for a FET.
I will try energising relay to see if it's operational.
I would buy a new unit but they are not available anymore.
Re: Hi and Newbie Question 333200N Transistor
In your first post, you said that three of the four "bridge rectifiers" were damaged. Why not try taking the undamaged one out, and checking with an ohm meter to see if it is a bridge rectifier or something else?
I don't think you will get far with playing anagrams with the number!
I don't think you will get far with playing anagrams with the number!
Re: Hi and Newbie Question 333200N Transistor
Fair one about anagrams David. I will have removed one of these 'bridge rectifiers and will test it.