timed open circuit on normally closed

Thanks oldspark, I never fully understood the practical differences between npn and pnp. I know the makeup and how they work, but never got what difference they made to a circuits behaviour

Actually (LOL...) I'm tempted to bet you know more than me! I merely knew - or applied the general rule - that the arrow in a symbol denotes the direction of travel of conventional current - ie, from +ve to -ve thru the load or device. Your arrow direction did not allow current to flow thru the load (speaker), hence it was wrong. Since I also recall the most common transistor (NPN) as having the arrow outward, therefore yours was PNP. Ok, I also knew a bit extra - like Vbe must be 0.7 or above for conduction and Vbe is +0.7 for NPN (versus -0.7 for PNP) - and applied that... tho that too was essentially rigged "graphical memory"... But notice my lack of confirmation that it will actually work? (No doubt spotted by experts and clear thinkers...) But according to my SIMPLE logical and graphical analysis it will. However, it is likely to be a soft or gradual turn off as any RC decay or rise circuit is - unless something causes it to be sharp. (IE - hysteresis thru clever circuitry or device characteristics; follow-on Schmidt triggers, etc.) And hence - to avoid the need for clever design, I agree with the use of a square wave (on-off) timer circuit - like DEI or 555 timers etc. FYI - my added misc comments include: - I disliked timers like DEI, but hey - they are relatively cheap; well designed (versatile); and require no assembly etc; - I often suggest the PICAXE 08 (08M2) in lieu of 555s because they are almost as cheap; use FAR less current; and are programmable (they have ADCs, a DAC, i2c comms interface; PWM outputs for dimming, etc). - But I certainly approve of your 'buffer' transistorised circuit with small C rather than a brute force big C direct on a relay coil. (IE - big kudos to you on your circuit!!! ) Anyhow, the above is FYI - and largely to offset your OP's "...first post so be gentle... ". Hey man, that works both ways! (At least in MY case.)