Hi all,
I realise that I don't post very much, but I've never really seen anything I can help with (my knowledge in electronics is not at a 'pro' level, but equally not at a 'noob' level either hopefully
).
I've started my first 'real' PICAXE project (I've just been playing around with various things so far); it's an RFID access control system for our new shed.
I've got a Parallax serial RFID module (~4.5V - which works extremely well, if anybody's interested), an electric door strike (~12V) and obviously an 08M PICAXE (I'm getting a larger chip shortly).
I've got the 'system' identifying certain RFID tags and bringing a pin high when authorised (which, in turn, lights an LED); so far, so good.
Although at this stage, I've run into two problems because of the higher voltage that the strike requires;
I assumed that I could just use a ~5V relay to turn the strike on when a PICAXE pin is brought high, but, even with all the advice I could find at the forum and the third manual, I can't seem to get the MOSFET to work properly (PICAXE -> MOSFET -> relay => strike).
I've used a MOSFET with a solar motor before and, after a few hours of trial and error, I got it working at the (almost) full 4.5V (unlike the ~3V from the PICAXE chip), but I didn't make any circuit diagram (assuming I'd remember later), so I'm stuck now :\
That's my first problem - my second problem is the fact that I have two circuits, one on 4.5V and another on 12V - I only wanted to use one regulated power adaptor to power the whole system, which I assumed would mean getting a 12V adaptor (for the strike) and then using a mini-step-down transformer inside (for the PICAXE + RFID module), but I'm not sure what I should be looking to buy or if it's even normal practice to use one power supply.
Thanks for reading - I know it's quite long, but I'm trying not to be that vague
I'd really appreciate any suggestions as I've spend almost an entire weekend messing around with the MOSFET just to get the full voltage correctly and trigger the relay, but haven't stumbled upon the solution yet. (any circuit diagrams/photos using a MOSFET correctly would be great if anybody has one)
I realise that I don't post very much, but I've never really seen anything I can help with (my knowledge in electronics is not at a 'pro' level, but equally not at a 'noob' level either hopefully

I've started my first 'real' PICAXE project (I've just been playing around with various things so far); it's an RFID access control system for our new shed.
I've got a Parallax serial RFID module (~4.5V - which works extremely well, if anybody's interested), an electric door strike (~12V) and obviously an 08M PICAXE (I'm getting a larger chip shortly).
I've got the 'system' identifying certain RFID tags and bringing a pin high when authorised (which, in turn, lights an LED); so far, so good.
Although at this stage, I've run into two problems because of the higher voltage that the strike requires;
I assumed that I could just use a ~5V relay to turn the strike on when a PICAXE pin is brought high, but, even with all the advice I could find at the forum and the third manual, I can't seem to get the MOSFET to work properly (PICAXE -> MOSFET -> relay => strike).
I've used a MOSFET with a solar motor before and, after a few hours of trial and error, I got it working at the (almost) full 4.5V (unlike the ~3V from the PICAXE chip), but I didn't make any circuit diagram (assuming I'd remember later), so I'm stuck now :\
That's my first problem - my second problem is the fact that I have two circuits, one on 4.5V and another on 12V - I only wanted to use one regulated power adaptor to power the whole system, which I assumed would mean getting a 12V adaptor (for the strike) and then using a mini-step-down transformer inside (for the PICAXE + RFID module), but I'm not sure what I should be looking to buy or if it's even normal practice to use one power supply.
Thanks for reading - I know it's quite long, but I'm trying not to be that vague

I'd really appreciate any suggestions as I've spend almost an entire weekend messing around with the MOSFET just to get the full voltage correctly and trigger the relay, but haven't stumbled upon the solution yet. (any circuit diagrams/photos using a MOSFET correctly would be great if anybody has one)